Soal Latihan Seleksi Masuk Ptn Set 1

The pH of blood in the human body is always constant because there are bicarbonate ions and dissolved CO2 in the blood, which act as buffering solutions. These buffering solutions help to maintain the pH level within a narrow range by absorbing excess hydrogen ions or releasing them when needed. This constant pH is essential for the proper functioning of enzymes and other biochemical processes in the body.

HCl dapat dibuat dengan cara memanaskan NaCl dengan H2SO4 pekat karena H2SO4 pekat tidak mengoksidasi Cl- menjadi Cl2. Namun, HI tidak dapat dibuat dengan cara yang sama karena H2SO4 pekat mudah mengoksidasi I- menjadi I2.

The given compound is Fe2(SO4)3, which means it contains 2 iron (Fe) atoms. The relative atomic mass of Fe is 56, so the total mass of iron in the compound is 2 x 56 = 112. Since the compound has a total mass of 4 grams, the mass of iron in 4 grams of Fe2(SO4)3 is 112/4 = 28 grams. However, the question asks for the mass in grams, so the answer is 28/100 = 1.12 grams.

When sodium carbonate (natrium karbonat) is added to dilute sulfuric acid, it produces carbon dioxide gas. This gas has the ability to turn limewater cloudy, indicating the presence of carbon dioxide. Therefore, natrium karbonat is the correct answer.

Vanadium dengan tingkat oksidasi +4 terdapat pada senyawa VOSO4. Pada senyawa ini, vanadium memiliki bilangan oksidasi +4 karena oksigen memiliki bilangan oksidasi -2 dan terdapat dua atom oksigen dalam senyawa ini. Selain itu, senyawa ini juga mengandung satu atom belerang dengan bilangan oksidasi +6 dan dua atom hidrogen dengan bilangan oksidasi +1.

A sol is a colloidal system formed by dispersing solid particles into a liquid. It consists of small particles that are evenly dispersed and do not settle down. Sol can be formed by adding a solid substance to a liquid and allowing it to disperse. This explanation aligns with the given correct answer, which is "sol".

The correct answer is 0,15x mol/L. This is because the question states that x mol of N2O has reacted, meaning that x mol of N2O has been converted into N2. Since the volume of the system is 10 L, the concentration of N2 in the equilibrium would be x mol divided by 10 L, which simplifies to 0,1x mol/L. However, the question asks for the concentration of N2, not N2O. Since N2 is produced in a 1:1 ratio with N2O, the concentration of N2 would also be 0,1x mol/L. Therefore, the correct answer is 0,15x mol/L.

The correct answer is amina because meskaline is a tranquilizer drug and it belongs to the group of amines.

The given information states that the solubility of CaCl2 in water at 0oC is approximately 5.4 molal. The question asks for the freezing point depression caused by a 0.54 molal solution of CaCl2. Freezing point depression is calculated using the formula ΔT = Kf * m, where ΔT is the change in temperature, Kf is the cryoscopic constant, and m is the molality of the solution. Plugging in the values, ΔT = 1.86 * 0.54 = 1.0oC. Therefore, the freezing point depression caused by a 0.54 molal solution of CaCl2 is 1.0oC, which means the freezing point of the solution is 0oC - 1.0oC = -1.0oC. Hence, the correct answer is 3.0oC.

The given information states that the combustion of a hydrocarbon compound CxHy produces 220 mg of CO2 and 45 mg of H2O. By using the molar mass of CO2 (44 g/mol) and H2O (18 g/mol), we can calculate the number of moles of each compound produced. From the given information, it can be inferred that the number of moles of carbon in the compound is equal to the number of moles of oxygen in CO2, which is 1. The number of moles of hydrogen in the compound is equal to the number of moles of hydrogen in H2O, which is 2. Therefore, the empirical formula of the compound is CH.

The correct answer is (1,5 a - b + c) kJ/mol. This can be determined by using the Hess's Law, which states that the enthalpy change of a reaction is independent of the pathway taken. In this case, we can consider the formation of NO2(g) as the sum of the formation of H2O(l) and NH3(g), with appropriate coefficients. Therefore, the enthalpy change for the formation of NO2(g) can be expressed as (1,5 a - b + c) kJ/mol.

Sakarosa adalah salah satu karbohidrat yang paling banyak diproduksi. Karbohidrat ini terdiri dari dua monosakarida, yaitu glukosa dan fruktosa, yang terikat oleh ikatan glikosidik. Sakarosa banyak ditemukan dalam gula tebu dan gula bit.

The incorrect statement in the given options is "kecepatan reaksi terkatalis tidak bergantung pada konsentrasi katalis" which translates to "the rate of a catalyzed reaction does not depend on the concentration of the catalyst." This statement is incorrect because the rate of a catalyzed reaction is indeed influenced by the concentration of the catalyst. A higher concentration of catalyst generally leads to a faster reaction rate, as the catalyst provides an alternative pathway with lower activation energy for the reaction to occur.

The correct answer states that X is found in the alkaline earth group and the bond between X and Y is ionic. This means that X belongs to the second group of the periodic table, which includes elements such as magnesium and calcium. The ionic bond between X and Y suggests that X will donate electrons to Y, resulting in the formation of a compound with the formula X2Y5.