Final Laboratorium Kimia Analisa 2018/2019

not-available-via-ai

An indicator is a substance that is added until the completion of a reaction, which is indicated by a change in color. In this context, an indicator is used to determine the endpoint or completion of a reaction by observing the color change. It helps in determining the presence or absence of certain substances in a solution.

The equation V NaOH x N NaOH = V HCl x N HCl is used for standardization. Standardization refers to the process of determining the exact concentration of a solution by comparing it to a known concentration of another solution. In this case, the equation is used to determine the concentration of NaOH by titrating it with a known concentration of HCl.

Teknik kromatografi kolom menghasilkan sampel yang lebih banyak. Ini berarti teknik ini mampu memisahkan dan mengumpulkan lebih banyak jumlah sampel dalam satu proses analisis. Hal ini dapat menghemat waktu dan usaha dalam memperoleh sampel yang dibutuhkan untuk analisis.

The correct answer is Pandanus amaryllifolius. This is because the other options have spelling variations or misspellings of the plant name. The correct spelling is Pandanus amaryllifolius, which refers to a species of plant commonly used in Thin Layer Chromatography experiments.

The correct answer is "Reaktan yang telah ditambahkan titran". In titration, the titrant is the solution of known concentration that is added to the analyte (the substance being analyzed) to determine its concentration. Therefore, the term "titree" refers to the analyte or reactant that has been added with the titrant during the titration process.

The correct answer is Serium (IV) sulfat. This is because the compound Ce(SO4)2 indicates that it contains one cerium ion (Ce) and two sulfate ions (SO4). The roman numeral IV in the name indicates that the cerium ion has a charge of +4. The term "sulfat" indicates that the compound contains sulfate ions. Therefore, the correct name for the compound is Serium (IV) sulfat.

The correct answer is "Titran". In the given context, it is stated that the buret is used to fill the solution for the titration process. The solution that is present in the buret is referred to as the "Titran".

The correct answer is "Nasi" because the question states that the sample that produces a dark brown stain when tested with cerium sulfate is the answer. Since nasi is mentioned as one of the samples on the table, it is the correct answer.

To calculate the amount of sulfuric acid needed to make a 15% solution, we can use the formula: (concentration of acid x volume of acid) = (concentration of solution x volume of solution).

Given that the concentration of the acid is 96% and the volume of the solution is 50 mL, we can plug these values into the formula: (96% x volume of acid) = (15% x 50 mL).

Simplifying the equation, we get: (0.96 x volume of acid) = (0.15 x 50 mL).

To find the volume of acid needed, we can rearrange the equation: volume of acid = (0.15 x 50 mL) / 0.96.

Solving this equation, we get: volume of acid = 7.82 mL.

Therefore, the correct answer is 7.82 mL.

The correct answer is "Memisahkan senyawa" because both KLT (Kromatografi Lapisan Tipis) and KK (Kromatografi Kertas) are chromatography techniques that are used to separate compounds based on their different affinities to the stationary phase. In both techniques, a sample mixture is applied to a solid support (such as a thin layer or paper) and a mobile phase (solvent) is passed through it. The compounds in the sample will interact differently with the stationary phase, causing them to separate and form distinct bands or spots. Therefore, "Memisahkan senyawa" (separating compounds) is the correct answer that describes the similarity between KLT and KK.

The correct answer is "Absorption." Absorption refers to the process in which one substance is taken up by another substance, typically resulting in the first substance being incorporated into the structure of the second substance. In the context of KLT NP-SiO2, it can be inferred that the NP-SiO2 material is capable of absorbing or incorporating other substances into its structure.

The correct answer is "Pp". The question asks for the indicator used in acidimetry titration. "Pp" is a common abbreviation for phenolphthalein, which is a commonly used indicator in acid-base titrations. Phenolphthalein is colorless in acidic solutions and turns pink or red in basic solutions, making it suitable for acidimetry titrations where the endpoint is reached when the solution turns pink or red.

KLT (Kromatografi Lapis Tipis) memiliki keunggulan dibandingkan dengan kolom dalam hal penggunaan eluen yang sedikit. Hal ini berarti KLT membutuhkan jumlah eluen yang lebih sedikit untuk menjalankan proses pemisahan bahan kimia. Penggunaan eluen yang sedikit dapat menghemat biaya dan waktu dalam proses kromatografi. Selain itu, penggunaan eluen yang sedikit juga dapat menghasilkan sampel yang lebih pekat dan berkualitas.

Based on the given information, the elution of the sample using a methanol:chloroform eluent with a ratio of 75:25 on a RP-C18 TLC plate resulted in an Rf value of 0.2. This suggests that the compound is polar. The polar compounds tend to have lower Rf values as they interact more strongly with the stationary phase (RP-C18) and are less soluble in the mobile phase (methanol:chloroform). Therefore, the compound in question is likely to be polar.

The given answer is in the correct order from polar to nonpolar solvents. Ethanol (EtOH) is a polar solvent due to the presence of the hydroxyl group. Ethyl acetate (EtOAc) is also polar but less so than EtOH. Dichloromethane (DCM) is a less polar solvent compared to EtOAc. Finally, n-Hexane is a nonpolar solvent with no polar functional groups. Therefore, the order from most polar to nonpolar solvents is EtOH - EtOAc - DCM - n-Hexane.

Kromofor adalah zat kimia yang memberikan warna pada suatu senyawa. Dalam kromatografi lapis tipis, kromofor berperan sebagai pembawa warna yang memungkinkan pemisahan dan identifikasi senyawa-senyawa yang terdapat dalam campuran. Kromofor ini akan berinteraksi dengan fase gerak dan fase diam (silica gel) untuk menghasilkan perbedaan dalam pergerakan dan retensi senyawa-senyawa tersebut. Klorofil juga merupakan kromofor, tetapi dalam konteks ini, kromofor secara umum lebih tepat sebagai jawaban karena dapat mencakup berbagai jenis zat kimia yang dapat memberikan warna pada kromatografi lapis tipis.

Based on the given image, there are five different compounds present in the sample.

Kolom bukan merupakan fase diam pada kromatografi karena kolom merupakan tempat di mana fase diam ditempatkan. Fase diam pada kromatografi adalah media yang tidak bergerak dan digunakan untuk memisahkan senyawa berdasarkan perbedaan afinitas mereka terhadap fase diam. Sephadex, Alumina, dan Silica adalah contoh fase diam yang umum digunakan dalam kromatografi.

The question is asking for the method used in the analysis of a positive alkalimetry test. The correct answer, "Analisa Kualitatif" (Qualitative Analysis), refers to the method used to determine the presence or absence of certain substances in a sample. In this case, the method is used to analyze the alkalinity of the sample, indicating whether it is positive or not. This method focuses on the qualitative properties of the sample rather than the quantitative measurements.

The given statement is true because polar solvents, which have a -OH group, can interfere with the separation of polar compounds on a polar stationary phase in thin-layer chromatography (TLC). This is because the polar solvents can dissolve the stationary phase and cause it to move along with the solvent front, resulting in poor separation. Therefore, it is recommended to use nonpolar solvents for polar TLC plates to achieve better separation.

The given options are different types of interactions in chromatography. Partition refers to the separation of compounds based on their solubility in two immiscible phases. Ion exchange involves the separation of ions based on their charge. Exclusion chromatography separates molecules based on their size. Molecular affinity chromatography is a technique that separates molecules based on their specific interactions with a ligand. Therefore, the correct answer is "Molecular affinity" because it does not represent a type of interaction in chromatography.

The correct answer is RP-C18. RP-C18 is a type of stationary phase used in reverse phase chromatography. In reverse phase chromatography, the stationary phase is nonpolar, while the mobile phase is polar. This means that compounds with higher polarity will have a higher affinity for the mobile phase and will elute faster, while less polar compounds will have a higher affinity for the stationary phase and will elute slower. Since the extract in question resulted in a spot with an Rf value of 0.4, it suggests that the extract is more polar and would have a higher affinity for the stationary phase of RP-C18.

The correct answer is "Partition." Partition refers to the separation of different components in a mixture based on their partition coefficients between the stationary and mobile phases in chromatography. In KLT RP-C18, the stationary phase is made up of a hydrophobic alkyl chain (C18) bonded to the silica surface, while the mobile phase is typically a mixture of organic solvents and water. The analytes in the mixture will partition between the stationary and mobile phases based on their hydrophobicity, allowing for separation and analysis.

The correct answer is 1:1, Serium dan asam sulfat. This means that the serum and sulfuric acid are mixed in a ratio of 1:1 to create the sulfate reagent.

The correct answer is 0.39%. To calculate the concentration of acetic acid in the solution, we can use the formula:

% concentration = (Volume of NaOH used * Normality of NaOH * Molecular weight of acetic acid) / (Volume of solution * 10)

In this case, the volume of NaOH used is 3.3 mL, the normality of NaOH is 0.1 N, the molecular weight of acetic acid is 60 g/mol, and the volume of the solution is 5 mL.

Plugging these values into the formula, we get:

% concentration = (3.3 mL * 0.1 N * 60 g/mol) / (5 mL * 10) = 0.39%

Therefore, the concentration of acetic acid in the solution is 0.39%.

The correct answer is MeOH: EtOAc (85:15 v/v) because this solvent composition provides the best conditions for obtaining a stain spot at an Rf value of 0.7 using KLT RP-C18 on a polar sample. The combination of methanol (MeOH) and ethyl acetate (EtOAc) in a ratio of 85:15 v/v ensures proper separation and retention of the components in the sample, resulting in the desired Rf value.

The given question is asking for the type of titration that is not included among the three mentioned types. The three types mentioned are argentometri, pengendapan, and kompleksasi. The correct answer, ionisasi, is the type of titration that is not included in the given options. Therefore, ionisasi is the correct answer for this question.

The correct answer is Eter dan n-Heksana. Eter (ethers) and n-Heksana (n-hexane) are both nonpolar solvents. Ethers have a symmetrical molecular structure and do not have any polar functional groups, making them nonpolar. n-Hexane is a hydrocarbon with only carbon and hydrogen atoms, and it also lacks any polar groups, making it nonpolar. Nonpolar solvents are commonly used for dissolving nonpolar compounds and for certain extraction processes.

The correct answer is MeOH: H2O (80:20 v/v) because the sample being analyzed is nonpolar, and RP-C18 is a reverse-phase chromatography column that is commonly used for the separation of nonpolar compounds. MeOH: H2O (80:20 v/v) is a polar solvent system that can effectively separate nonpolar compounds on the RP-C18 column. The 80:20 ratio of MeOH to H2O ensures a suitable polarity for the separation, with MeOH providing the necessary solubility for the nonpolar sample.

Penambahan CH3COOH bertujuan untuk menaikkan tingkat kepolaran sampel. Hal ini karena CH3COOH merupakan asam asetat yang bersifat polar. Dengan menambahkan CH3COOH ke dalam pelarut, akan terjadi peningkatan polaritas pelarut tersebut. Hal ini akan mempengaruhi polaritas sampel polar yang larut di dalamnya, sehingga tingkat kepolaran sampel akan meningkat.

The given information states that a sample eluted using a NP-SiO2 plate with chloroform:ethyl acetate eluent has an Rf value of 0.6. Based on this, it can be inferred that the compound in question has a moderate affinity for the stationary phase (NP-SiO2) and the mobile phase (chloroform:ethyl acetate). This suggests that the compound is semi polar, meaning it has some polarity but also some nonpolar characteristics.

The correct answer is MeOH:CHCl3 (50:50) because it is the solvent mixture that Rita used to elute sample X on the NP-SiO2 plate. Therefore, it would be logical for her to use the same solvent mixture as the eluent in the column chromatography.

The correct answer is n-Heksana - DCM - CHCl3 - EtOAc - EtOH - MeOH. This is because the polarity of a solvent is determined by its ability to dissolve polar or nonpolar substances. As we move from left to right in the given list, the solvents become progressively more polar. n-Heksana is a nonpolar solvent, DCM (Dichloromethane) is a slightly polar solvent, CHCl3 (Chloroform) is a moderately polar solvent, EtOAc (Ethyl Acetate) is a polar solvent, EtOH (Ethanol) is a more polar solvent, and MeOH (Methanol) is the most polar solvent in the list. Therefore, the solvents are arranged from nonpolar to polar.

The correct answer is n-Heksana 100%. This is because n-Heksana is a non-polar solvent, which is suitable for a polar sample. The other solvents listed (MeOH, EtOAc, DCM) are polar solvents and would not be appropriate for obtaining a stain on Rf=0.2 using a polar sample.

The correct answer is EtOAc: n-Heksana (10:90 v/v) because the given Rf value of 0.4 indicates that the compound being separated is more polar and has a higher affinity for the mobile phase (EtOAc) than the stationary phase (n-Heksana). The composition of 10:90 v/v means that the mobile phase is primarily composed of n-Heksana, which is nonpolar, and a small amount of EtOAc, which is polar. This composition allows for effective separation and retention of the compound on the stationary phase, resulting in a distinct spot with an Rf value of 0.4.

In thin layer chromatography (KLT), the stationary phase is a solid material that is coated on a plate or sheet, and in this case, it is cellulose. The stationary phase acts as the surface on which the compounds in the mixture will interact and separate based on their affinity for the stationary phase. Therefore, cellulose is the correct answer as it is the stationary phase in thin layer chromatography.

The correct answer is "Semipolar". This is because the extract is spotted on a KLT plate using a solvent mixture of n-Hexane and EtOAC. The Rf value of 0.4 suggests that the compound has a moderate affinity for both the polar and nonpolar phases of the KLT plate. Therefore, it can be classified as semipolar.

Izza menutup chamber dengan penutupnya agar eluen dapat menjenuh dan tetap stabil selama proses pengelusian. Dengan menjenuhkan eluen, konsentrasi pelarut akan tetap konstan dan tidak berkurang selama penggunaan. Hal ini penting untuk memastikan kualitas dan konsistensi hasil sampel yang dielusi. Penutupan chamber juga mencegah pelarutnya menguap, sehingga penggunaan pelarut menjadi lebih hemat.

Based on the given information, Riska used a non-polar eluent (n-Hexane:ethyl acetate) for the thin layer chromatography (TLC) on NP-SiO2 plate. The fact that the sample eluted with an Rf value of 0.3 suggests that it has a similar polarity to the eluent, which is non-polar. Therefore, the correct answer is "Non polar".

The correct answer is "Menggunakan eluen metanol 100%, karena seharusnya mencampurkan dengan pelarut yang lain". The reason for this is that elution is a process in chromatography where the components of a mixture are separated by their affinity for the eluent. In this case, Yuni used 100% methanol as the eluent, which may not be suitable for separating the desired compounds effectively. It is recommended to use a mixture of solvents to achieve better separation and elution of the compounds of interest.

The correct answer is EtOAc: MeOH (90:10 v/v) because this solvent system has a higher polarity compared to the other options. Since the sample is semipolar, a more polar solvent system is needed to elute the sample effectively. EtOAc: MeOH (90:10 v/v) provides a good balance between the nonpolar ethyl acetate and the polar methanol, making it suitable for eluting semipolar compounds.

The correct answer is DCM 100%. DCM (Dichloromethane) is a nonpolar solvent, which means it has low polarity. In reverse-phase chromatography using RP-C18, the stationary phase is polar while the mobile phase should be nonpolar. By using a nonpolar solvent like DCM, the student can achieve a higher Rf value of 0.9, indicating that the compound of interest will migrate further up the chromatogram.