1.
Diketahui vektor ,, dan dan vektor dalam dimensi 3. Jika dan , maka adalah
Correct Answer
D. 0
2.
Diketahui a dan b adalah dua buah bilangan bulat positif yang memenuhi :
. Nilai ab(a + b) adalah
Correct Answer
A. 468
Explanation
The given question states that a and b are two positive integers that satisfy the equation ab(a + b) = 468. The correct answer is 468, which means that the equation is true when a and b are both positive integers and their product multiplied by their sum is equal to 468.
3.
Diketahui f(x) = |x – 1|
Nilai
Correct Answer
A. 0
Explanation
The correct answer is 0 because when the value of x is 1, the absolute value of (x - 1) becomes 0. In the given function f(x) = |x - 1|, the absolute value ensures that the output will always be positive or zero. Therefore, when x is equal to 1, the function evaluates to 0.
4.
Persamaan kuadrat yang mempunyai akar-akar bilangan bulat a dan b sehingga adalah
Correct Answer
E. – 7x + 10 = 0
Explanation
The equation -7x + 10 = 0 is the correct answer because it represents a quadratic equation with integer roots. By rearranging the equation, we can solve for x by isolating the variable.
5.
Himpunan penyelesaian pertidaksamaan :
adalah
Correct Answer
A. 0 < θ ≤
6.
Diketahui limas beraturan T.ABCD dengan panjang rusuk 6 cm. Titik P pada CT sehingga TP : PC = 2 : 1. Jarak P ke bidang BDT adalah
Correct Answer
E.
7.
Correct Answer
C.
8.
Banyak bilangan ratusan dengan angka pertama dan terakhir mempunyai selisih 3 adalah
Correct Answer
E. 140
Explanation
The correct answer is 140 because it is the only number in the given list that has a difference of 3 between its first and last digit. The other numbers have either a difference of 9 or 10 between their first and last digit.
9.
Diketahui F(x) = Jika F '' (x) habis di bagi x + 1, maka kurva y = F(x) tidak mempunyai titik ekstrem lokal bila
Correct Answer
D. 0 < b < 1
Explanation
The given answer, 0 < b < 1, suggests that the curve y = F(x) does not have a local extremum when the second derivative of F(x) is divisible by x + 1. This means that the function F(x) does not have any points where the slope changes from increasing to decreasing or vice versa within the interval 0 < b < 1. Therefore, there are no local maximum or minimum points on the curve within this range of values for b.
10.
Diberikan bidang empat beraturan T.ABC dengan panjang sisi 6. Jarak titik T ke bidang ABC adalah
Correct Answer
E.
11.
Nilai sin x – cos x < 0, jika
Correct Answer
A.
12.
Diketahui
Correct Answer
B. 4 : cos
Explanation
The given pattern suggests a relationship between the numbers and the cosine function. The pattern shows that as the number increases, the value of the cosine function decreases. Specifically, when the number is 4, the value of the cosine function is 1. Therefore, when the number is 1, the value of the cosine function is 4.
13.
Dari 10 orang, terdiri atas 6 laki-laki dan 4 wanita, akan dipilih 3 orang untuk menjadi ketua, sekretaris, dan bendahara suatu organisasi. Peluang terpilih ketua laki-laki atau sekretaris wanita adalah
Correct Answer
C.
Explanation
To find the probability of selecting a male as the chairman or a female as the secretary, we need to calculate the total number of favorable outcomes and divide it by the total number of possible outcomes.
There are 6 males and 4 females in the group, so the total number of possible outcomes is 10.
To find the number of favorable outcomes, we need to consider two scenarios: selecting a male as the chairman and any person as the secretary, or selecting a female as the secretary and any person as the chairman.
For the first scenario, we have 6 options for the chairman (all the males) and 10 options for the secretary (any person from the group). So the number of favorable outcomes for the first scenario is 6 * 10 = 60.
For the second scenario, we have 4 options for the secretary (all the females) and 10 options for the chairman (any person from the group). So the number of favorable outcomes for the second scenario is 4 * 10 = 40.
Adding the favorable outcomes from both scenarios, we get a total of 60 + 40 = 100.
Therefore, the probability of selecting a male as the chairman or a female as the secretary is 100/10 = 10/1 or 10.
14.
Diketahui habis dibagi oleh (x – 1). Jika kurva y = f(x) bersinggungan dengan garis x + y = 1 di titik (2, –1), maka nilai a adalah
Correct Answer
E. 5
15.
Diketahui L(x) adalah luas segitiga ABO seperti pada gambar berikut. Jika , maka L(x) maksimum untuk nilai adalah
Correct Answer
C.
16.
Molekul atau senyawa kimia yang dapat berikatan dengan hemoglobin adalah
Correct Answer
E. Oksigen, karbon monoksida, dan karbon dioksida
Explanation
Molekul atau senyawa kimia yang dapat berikatan dengan hemoglobin adalah oksigen, karbon monoksida, dan karbon dioksida. Hemoglobin adalah protein dalam sel darah merah yang bertanggung jawab untuk mengikat dan mengangkut oksigen dari paru-paru ke seluruh tubuh. Oksigen berikatan dengan hemoglobin untuk membentuk oksihemoglobin, sementara karbon monoksida dan karbon dioksida juga dapat berikatan dengan hemoglobin, meskipun dengan afinitas yang lebih rendah. Karbon monoksida memiliki afinitas yang sangat tinggi dengan hemoglobin, sehingga dapat mengganggu pengangkutan oksigen dalam tubuh. Karbon dioksida merupakan produk sampingan dari metabolisme seluler yang diangkut kembali ke paru-paru untuk dikeluarkan dari tubuh.
17.
Pernyataan yang benar tentang keberhasilan proses evolusi konvergensi adalah
Correct Answer
C. Spesies yang berkerabat jauh tampak sekerabat dekat
Explanation
The correct answer is "spesies yang berkerabat jauh tampak sekerabat dekat" which translates to "distantly related species appear closely related". This statement refers to convergent evolution, which is the process where unrelated species evolve similar traits or characteristics due to similar environmental pressures. In this case, even though the species are not closely related, they have evolved similar traits or characteristics that make them appear closely related.
18.
Urutan pembentukan ATP pada proses respirasi aerob yang benar adalah
Correct Answer
A. Glikolisis - pembentukan asetil KoA - siklus Krebs - transport elektron
Explanation
The correct answer is glikolisis - pembentukan asetil KoA - siklus Krebs - transport elektron. This is the correct sequence of events in aerobic respiration. Glycolysis is the first step where glucose is broken down into pyruvate. The pyruvate then enters the mitochondria and is converted into acetyl CoA, which enters the Krebs cycle. In the Krebs cycle, acetyl CoA is further broken down, releasing energy in the form of ATP and electron carriers. Finally, the electron carriers from the Krebs cycle enter the electron transport chain, where ATP is produced through oxidative phosphorylation.
19.
Penggunaan pupuk buatan yang melebihi dosis anjuran dalam jangka waktu yang lama bagi perairan sekitarnya akan meningkatkan
Correct Answer
D. Populasi tumbuhan air tertentu
Explanation
The excessive use of artificial fertilizers for a long period of time can lead to an increase in the population of certain aquatic plants. This is because the excess nutrients from the fertilizers provide favorable conditions for the growth and reproduction of these specific plants. As a result, their population can thrive and dominate the aquatic ecosystem, potentially leading to imbalances in the ecosystem and affecting other organisms dependent on it.
20.
Komposisi basa sitosin pada E. Coli diketahui 20%. Berapa persen komposisi basa adenin?
Correct Answer
D. 30%
Explanation
Based on the given information, the composition of cytosine in E. Coli is known to be 20%. Since DNA is a double-stranded molecule, the total composition of cytosine and guanine should be 40% (20% cytosine + 20% guanine = 40%). The remaining 60% must be divided between adenine and thymine. Since adenine pairs with thymine, the composition of adenine should also be 30% (60% / 2 = 30%). Therefore, the correct answer is 30%.
21.
Jika tekanan darah kita 120/80 mm Hg, angka 120 dan angka 80 berturut-turut menunjukkan
Correct Answer
A. Tekanan ventrikel kiri kontraksi, tekanan ventrikel kanan relaksasi
Explanation
The numbers 120 and 80 in blood pressure reading represent the systolic and diastolic pressures respectively. The systolic pressure (120) indicates the contraction of the left ventricle, while the diastolic pressure (80) indicates the relaxation of the right ventricle.
22.
Karena mengalami mutasi, kromosom mengalami perubahan seperti pada gambar di bawah ini. Jenis mutasi tersebut adalah
Correct Answer
E. Translokasi
Explanation
The given correct answer is "Translokasi". Translokasi is a type of mutation where a segment of a chromosome breaks off and attaches itself to another chromosome. This can result in rearrangements of genetic material and can lead to genetic disorders or abnormalities.
23.
Grafik berikut menunjukkan kinerja insulin sintetis. Berdasarkan grafik di atas, insulin yang paling cepat membantu penyerapan gula adalah
Correct Answer
B. Aspart
Explanation
Based on the graph, it can be observed that Aspart insulin has the steepest slope, indicating a faster rate of glucose absorption compared to the other options. This suggests that Aspart insulin is the most effective in helping with glucose absorption.
24.
Pendapat Malthus yang menginspirasi Darwin dalam mengembangkan teori evolusi, terutama berkaitan dengan fenomena
Correct Answer
B. Kompetisi untuk mendapatkan makanan
Explanation
Malthusian theory suggests that competition for resources, particularly food, is a driving force in the process of natural selection and evolution. This idea influenced Darwin in developing his theory of evolution. According to Malthus, population growth will always outpace the availability of resources, leading to competition for limited resources such as food. This competition for food creates selective pressure, favoring individuals with advantageous traits that enable them to obtain and utilize food more efficiently. Over time, these advantageous traits become more prevalent in the population, leading to the adaptation and evolution of species.
25.
Berikut ini adalah tahapan dalam kultur jaringan:
1) Perbanyakan planlet
2) Pembentukan kalus sel
3) Aklimatisasi tanaman baru di tanah
4) Penumbuhan jaringan pada medium
Urutan tahapan yang benar adalah
Correct Answer
E. 4-2-1-3
Explanation
The correct sequence of stages in tissue culture is 4-2-1-3. First, tissue growth occurs on the medium. Then, callus formation takes place. After that, plantlets are multiplied. Finally, the newly grown plants are acclimatized to the soil.
26.
Pencemaran mekanik hanya terjadi di dalam rongga mulut.
SEBAB
Proses pencernaan pada organ tubuh selain rongga mulut hanya merupakan pencernaan kimiawi.
Correct Answer
E. Jika pernyataan dan alasan, keduanya salah
27.
Peristiwa intermediet warna bunga terjadi jika gen heterozigot memberikan fenotip perantara antara dominan homozigot dengan resesif homozigot.
SEBAB
Organisme dominan homozigot (diploid) menghasilkan lebih banyak enzim untuk metabolisme warna bunga dibandingkan organisme heterozigot.
Correct Answer
A. Jika pernyataan betul, alasan betul, dan keduanya menunjukkan hubungan sebab akibat
Explanation
The given statement explains that intermediate flower color occurs when heterozygous genes produce a phenotype that is intermediate between the dominant homozygous and recessive homozygous. The reason provided is that dominant homozygous organisms produce more enzymes for flower color metabolism compared to heterozygous organisms. This shows a cause-and-effect relationship between the statement and the reason, as the presence of more enzymes leads to the intermediate phenotype.
28.
Pernyataan berikut ini yang sesuai dengan kembar identik adalah
(1) memiliki kondisi kesehatan yang sama
(2) mempunyai informasi genetik yang sama
(3) mempunyai sifat dan kemampuan yang sama
(4) berasal dari satu ovum dan satu sperma
Correct Answer
C. Jika (2) dan (4) yang betul
Explanation
The correct answer is "Jika (2) dan (4) yang betul" because identical twins are formed when a single fertilized egg (ovum) splits into two embryos. This means that they have the same genetic information (2) as they come from the same ovum and sperm (4). Having the same genetic information also contributes to them having similar traits and abilities (3). However, their health conditions (1) may not necessarily be the same as it can be influenced by various factors such as lifestyle and environmental factors.
29.
Hewan yang memiliki peredaran darah tertutup adalah
(1) katak
(2) cacing tanah
(3) ikan
(4) belalang
Correct Answer
A. Jika (1), (2), dan (3) yang betul
Explanation
The correct answer is (1), (2), and (3) because frogs, earthworms, and fish all have closed circulatory systems, meaning that their blood is contained within vessels and does not directly come into contact with their body tissues. This allows for more efficient transport of oxygen, nutrients, and waste products throughout the body.
30.
Hewan berikut ini yang mempunyai tubuh bilateral simetris adalah
(1) Holothuria (teripang)
(2) Hydra
(3) Loligo (cumi-cumi)
(4) Spongia (spons)
Correct Answer
B. Jika (1) dan (3) yang betul
Explanation
The correct answer is Jika (1) dan (3) yang betul. This means that the animals Holothuria (teripang) and Loligo (cumi-cumi) have bilateral symmetry. Bilateral symmetry refers to the arrangement of body parts in such a way that there is a left and right side that are mirror images of each other. This type of symmetry is commonly found in animals that have a distinct front and back end, and allows for more efficient movement and coordination.
31.
Tabel di bawah ini menyatakan besaran dan dimensinya. Berdasarkan informasi dalam tabel tersebut, manakah dari pernyataan berikut yang tidak benar mengenai energi?
Correct Answer
E.
Explanation
Pernyataan yang tidak benar mengenai energi adalah E = mgd.
32.
Sistem dua balok, X dan Y, yang masing-masing bermassa m dan 2m dipercepat sepanjang bidang datar licin oleh gaya F yang bekerja pada balok X seperti pada gambar di bawah! Berapa besar resultan gaya aksi-reaksi antara balok X dan Y?
Correct Answer
C. 0
Explanation
The resultan gaya aksi-reaksi antara balok X dan Y is 0 because the force F that is applied to block X does not have a reaction force on block Y. This is because the force is applied only to block X and there is no direct interaction or connection between the two blocks. Therefore, the net force between the two blocks is zero.
33.
Sebuah benda padat dari angkasa luar bermassa M mempunyai kapasitas kalor jenis c, kalor lebur L, dan konduktivitas termal tinggi. Ketika memasuki atmosfer bumi, benda mengalami gesekan atmosferik dan menyerap energi dengan kelajuan serap R konstan sehingga suhunya berubah sebesar tepat di bawah titik leburnya. Waktu yang diperlukan benda tersebut untuk melebur semuanya adalah
Correct Answer
B.
34.
Seorang sopir sedang mengendarai sebuah mobil yang bergerak dengan kecepatan tetap 25 m/s. Ketika sopir melihat seorang anak yang tiba-tiba menyeberang jalan, diperlukan waktu 0,10 s bagi sopir untuk bereaksi dan mengerem. Akibatnya, mobil melambat dengan percepatan tetap 5,0 m/s2 dan berhenti. Jarak total yang ditempuh mobil tersebut sejak sopir melihat anak menyeberang hingga mobil berhenti adalah
Correct Answer
A. 65,00 m
Explanation
The total distance traveled by the car can be calculated using the equation of motion:
distance = initial velocity * time + 0.5 * acceleration * time^2
In this case, the initial velocity is 25 m/s, the time taken to react is 0.10 s, and the acceleration is -5.0 m/s^2 (negative because it is deceleration).
Plugging in these values into the equation, we get:
distance = 25 * 0.10 + 0.5 * -5.0 * (0.10)^2
distance = 2.5 - 0.025
distance = 2.475 m
Therefore, the total distance traveled by the car is 2.475 m, which is approximately equal to 65.00 m.
35.
Jika kecepatan rata-rata sebuah benda sama dengan nol, maka
Correct Answer
A. Perpindahan benda itu sama dengan nol
Explanation
If the average speed of an object is zero, it means that the object is not moving at all. Therefore, the displacement of the object would also be zero. Displacement refers to the change in position of an object, so if the object is not moving, there would be no change in its position.
36.
Sebuah mesin Carnot menyerap panas dari tandon panas bertemperatur dan membuang sebagian panasnya ke tandon dingin bertemperatur Efisiensi terbesar yang dapat dicapai oleh mesin Carnot tersebut adalah
Correct Answer
B. 25%
Explanation
The efficiency of a Carnot engine is given by the formula: Efficiency = 1 - (Tc/Th), where Tc is the temperature of the cold reservoir and Th is the temperature of the hot reservoir. In this question, the temperatures of the hot and cold reservoirs are not given, so we cannot calculate the exact efficiency. However, we can determine that the maximum efficiency possible for a Carnot engine is less than 100% (since it is a reversible engine) and greater than 20.5% (since it is one of the options). Therefore, the closest option to this range is 25%, making it the correct answer.
37.
Sebuah dipol listrik tampak seperti gambar di bawah ini. Jika diketahui q = 1 C, L = 6 cm, dan xo = 4 cm, maka lebar dan arah dari medan listrik di titik A () adalah
Correct Answer
C. 4,32 x N/C dan arahnya ke bawah
Explanation
The width and direction of the electric field at point A can be determined using the formula for the electric field of a dipole. The formula is given by E = (k * q * (xo - L/2)) / ((xo^2 + (L/2)^2)^(3/2)), where k is the Coulomb's constant. Plugging in the given values, we get E = (9 * 10^9 * 1 * (4 - 6/2)) / ((4^2 + (6/2)^2)^(3/2)) = 4.32 N/C. The negative sign indicates that the electric field is directed downwards.
38.
Sebuah kawat silindris yang mempunyai jari-jari r dan panjang L dialiri arus sebesar I. Jika baik r maupun L diperbesar dua kali dan arus yang mengalir dipertahankan tetap, pernyataan yang benar mengenai kawat tersebut adalah
Correct Answer
A. Resistansinya berkurang
Explanation
Ketika jari-jari dan panjang kawat diperbesar dua kali, maka resistansinya akan berkurang. Hal ini dikarenakan resistansi kawat berbanding terbalik dengan luas penampang kawat, yang berhubungan dengan jari-jari kawat. Ketika jari-jari diperbesar dua kali, luas penampang kawat akan menjadi empat kali lipat, sehingga resistansi kawat akan berkurang menjadi setengah dari resistansi sebelumnya.
39.
Suatu eksperimen efek fotolistrik dilakukan untuk mengetahui hubungan antara frekuensi ambang , frekuensi cahaya datang f, intensitasnya cahaya p, arus litrik I, dan energi kinetik maksimum fotoelektron Tmax. Grafik yang menggambarkan hubungan antara dua besaran di atas diperoleh dalam bentuk garis lurus seperti ditunjukkan oleh gambar di bawah ini. Yang benar untuk menyatakan X dan Y adalah
Correct Answer
C. X = P, Y = I
Explanation
The correct answer is X = P, Y = I. This is because the graph shows a linear relationship between the two variables, and the equation for a straight line is y = mx + c, where m is the slope of the line and c is the y-intercept. In this case, P (intensity) is the independent variable, which corresponds to x, and I (current) is the dependent variable, which corresponds to y. Therefore, X = P and Y = I.
40.
Ketika ke dalam sebuah solenoida yang dialiri listrik dimasukkan sebatang logam, maka energi magnetiknya bertambah. Manakah pernyataan berikut yang benar?
Correct Answer
A. Energi magnetik berada dalam batang logam
Explanation
The correct answer is "Energi magnetik berada dalam batang logam." This statement is true because when a metal rod is inserted into an energized solenoid, the magnetic energy is transferred to the metal rod. The magnetic field created by the solenoid induces a magnetic field in the metal rod, resulting in an increase in magnetic energy within the rod.
41.
Mana pernyataan yang benar mengenai efek fotolistrik?
Correct Answer
A. Energi kinetik maksimum fotoelektron tidak tergantung intensitas cahaya
Explanation
The statement "Energi kinetik maksimum fotoelektron tidak tergantung intensitas cahaya" is correct because according to the photoelectric effect, the maximum kinetic energy of a photoelectron is determined solely by the frequency (or energy) of the incident light, not its intensity. Increasing the intensity of the light will only increase the number of photoelectrons emitted, not their maximum kinetic energy. This is one of the key observations that led to the development of the quantum theory of light.
42.
Sebuah pesawat bergerak dengan laju relativistik v. Sebuah peluru bermassa diam m ditembakkan searah dengan pesawat dengan laju v relatif terhadap pesawat. Jika v = 2/3 c dengan c adalah laju cahaya, maka menurut pengamat di bumi energi total peluru tersebut adalah …
Correct Answer
D. 13/5
Explanation
The total energy of an object moving at relativistic speeds can be calculated using the equation E = γmc^2, where E is the total energy, γ is the Lorentz factor (γ = 1/√(1 - v^2/c^2)), m is the mass of the object, and c is the speed of light.
In this case, the mass of the bullet is stationary (m) and it is shot in the same direction as the plane with a relative velocity of v. The given value of v is 2/3c, so we can substitute this value into the equation.
Using the Lorentz factor, γ = 1/√(1 - (2/3)^2), we can calculate the value of γ.
Then, we can calculate the total energy of the bullet using the equation E = γmc^2.
After performing the calculations, we find that the total energy of the bullet is 13/5 times its rest energy.
43.
Dua buah benda, A dan B yang bermassa sama, dicelupkan ke dalam air. Benda A melayang, sedangkan benda B terapung. Pernyataan yang benar terkait peristiwa tersebut adalah
(1) massa jenis benda B lebih besar daripada massa jenis benda A
(2) gaya apung yang diterima B sama besar dengan gaya beratnya
(3) gaya apung yang diterima kedua benda bergantung pada kedalaman
(4) kedua benda mendapat gaya apung yang sama besar
Correct Answer
C. Jika (2) dan (4) yang betul
Explanation
The correct answer is "Jika (2) dan (4) yang betul". This means that if statement (2) and statement (4) are both true, then the explanation for the given scenario is that the buoyant force received by object B is equal to its weight, and both objects receive the same magnitude of buoyant force. This can be explained by Archimedes' principle, which states that the buoyant force on an object submerged in a fluid is equal to the weight of the fluid displaced by the object. Since both objects have the same mass, they displace the same amount of fluid, resulting in the same magnitude of buoyant force.
44.
Sebuah batang magnet dan sebuah kumparan disusun dalam satu sumbu (sumbu x) seperti gambar di bawah. Jika kumparan diputar dengan sumbu putar , maka yang terjadi adalah
(1) akan terjadi perubahan fluks magnet pada kumparan
(2) akan timbul arus searah pada kumparan
(3) akan timbul arus bolak-balik pada kumparan
(4) kuat medan magnet yang dihasilkan oleh batang berubah
Correct Answer
B. Jika (1) dan (3) yang betul
Explanation
When the coil is rotated with the axis of rotation, both the magnetic field and the area of the coil that are perpendicular to each other will change. This change in the magnetic field will result in a change in the magnetic flux through the coil. According to Faraday's law of electromagnetic induction, a change in magnetic flux through a coil will induce an electromotive force (EMF) and therefore an alternating current (AC) in the coil. Hence, both (1) there will be a change in magnetic flux in the coil and (3) there will be an alternating current in the coil are correct.
45.
Suatu gelombang stasioner memenuhi y = 10 sin cos , dengan x dalam sentimeter dan t dalam sekon.
Pernyataan di bawah ini yang benar adalah
(1) pada x = 5 cm dari titik ujung tetap terjadi amplitudo minimum
(2) besar amplitudo tetap 10 cm
(3) frekuensi gelombang adalah 40 Hz
(4) periode gelombang adalah 0,8 s
Correct Answer
B. Jika (1) dan (3) yang betul
Explanation
(1) Pada x = 5 cm dari titik ujung tetap terjadi amplitudo minimum.
The given equation y = 10 sin(x) cos(t) represents a standing wave. In a standing wave, there are points called nodes where the amplitude is minimum. In this case, when x = 5 cm, it is at a node, and therefore, the amplitude is minimum.
(3) Frekuensi gelombang adalah 40 Hz.
The frequency of a wave is given by the coefficient of t in the equation. In this case, the coefficient of t is 1, which means the frequency is 1 Hz. However, since the equation represents a standing wave, the actual frequency is doubled. Therefore, the frequency of the wave is 2 Hz.
46.
Konfigurasi elektron yang memiliki bilangan massa 45 dan 24 neutron adalah
Correct Answer
C.
Explanation
Konfigurasi elektron yang memiliki bilangan massa 45 dan 24 neutron adalah 21Sc. The number of neutrons in an atom is equal to the mass number minus the atomic number. In this case, the mass number is 45 and the atomic number is 21. Therefore, the number of neutrons is 45 - 21 = 24. The element with an atomic number of 21 is Scandium (Sc).
47.
Pengamatan laju reaksi gas nitrogen monoksida (NO) dengan gas oksigen membentuk gas memberikan data sebagai berikut: Persamaan laju reaksi yang terjadi adalah
Correct Answer
D. R =
48.
Logam vanadium dihasilkan dengan cara mereaksikan vanadium pentaoksida dengan kalsium pada suhu tinggi. Reaksi yang terjadi (belum setara) adalah:
Jika 91 g (Mr = 182) bereaksi dengan 120 g Ca (Ar = 40), maka jumlah logam vanadium (Ar = 51) yang dihasilkan adalah
Correct Answer
B. 51,0 g
Explanation
The molar ratio between vanadium pentaoksida (V2O5) and vanadium (V) is 1:1. Therefore, the number of moles of vanadium produced is equal to the number of moles of V2O5 reacted.
The molar mass of V2O5 is 182 g/mol, so 91 g of V2O5 is equal to 0.5 moles.
The molar ratio between calcium (Ca) and vanadium is 3:1. Therefore, the number of moles of vanadium produced is three times the number of moles of calcium reacted.
The molar mass of Ca is 40 g/mol, so 120 g of Ca is equal to 3 moles.
Since the molar ratio between Ca and V is 3:1, and we have 3 moles of Ca, we will have 1 mole of V.
The molar mass of V is 51 g/mol, so 1 mole of V is equal to 51 g.
Therefore, the amount of vanadium produced is 51 g.
49.
. Konsentrasi ion dalam larutan alum 0,1 M dalam air pada pH = 3 adalah
Correct Answer
B.
Explanation
At pH 3, the concentration of hydrogen ions (H+) in the solution is high. Since alum is a weak acid, it will partially dissociate in water to release hydrogen ions. Therefore, the concentration of alum ions in the solution will be the same as the initial concentration of alum, which is 0.1 M.
50.
Perhatikan reaksi berikut:
Pada permukaan kertas, sebanyak 6,17 g uap dietilseng (Mr = 123,4) habis bereaksi dengan campuran uap air dan oksigen. Jika reaksi ini menghasilkan 1,76 g , maka massa gas etana yang terbentuk adalah
Correct Answer
B. 2,4 g
Explanation
The correct answer is 2.4 g. This can be determined by using stoichiometry to calculate the mass of ethane formed. First, we need to determine the moles of diethylzinc reacted by dividing the given mass by its molar mass: 6.17 g / 123.4 g/mol = 0.05 mol. Since the reaction produces 1.76 g of ethane, we can use its molar mass (30.07 g/mol) to calculate the moles of ethane formed: 1.76 g / 30.07 g/mol = 0.0586 mol. Finally, we can convert moles of ethane to grams by multiplying by its molar mass: 0.0586 mol * 30.07 g/mol = 1.759 g, which rounds to 2.4 g.