1.
Batu kapur sebanyak 30 gram dicampur dengan asam klorida 6,72 L (STP), sesuai persamaan reaksi berikut.CaCO3 (s) + 2HCl (g) -- > CaCl2(aq) + H2O (l) + CO2 (g)Volume gas yang dihasilkan jika diukur dalam keadaan standar sebanyak...L (Ar C=12, O= 16, Ca= 40, H= 1 dan Cl= 35,5)
Correct Answer
C. 3,36
Explanation
The balanced chemical equation shows that for every 1 mole of CaCO3 reacted, 1 mole of CO2 gas is produced. The molar mass of CaCO3 is 100 g/mol, so 30 g of CaCO3 is equal to 0.3 mol. Therefore, 0.3 mol of CO2 gas will be produced. According to Avogadro's law, 1 mole of gas at STP occupies 22.4 L. Therefore, 0.3 mol of CO2 gas will occupy 0.3 x 22.4 = 6.72 L.
2.
Pada reaksi antara logam magnesium sebanyak 10 gram dengan 6 gram oksigen sesuai persamaan reaksi:2Mg (s) + O2(g) -- > 2MgO (s) Ternyata dari percobaan dihasilkan 15 gram magnesium oksida sebanyak 1 gram. Kenyataan ini sesuai hukum....(Ar Mg= 24, O=16)
Correct Answer
D. Proust
Explanation
The answer is Proust because it is based on the law of definite proportions. According to this law, a compound always contains the same elements in the same ratio by mass. In this case, the ratio between magnesium and oxygen in magnesium oxide is 2:1. The given experimental result of 15 grams of magnesium oxide formed from 1 gram of magnesium confirms this ratio, supporting Proust's law.
3.
Perhatikan persamaan reaksi berikut ini!Mg (s) + 2 HCl (aq) -- > MgCl2 (aq) + H2 (g)Apabila 4 gram logam Mg dimasukkan ke dalam 10 ml larutan HCl 2 M, volume gas H2 yang terbentuk dalam keadaan standar adalah... (Ar Mg= 24, H= 1, Cl= 35,5)
Correct Answer
A. 0,224 L
Explanation
The given equation represents the reaction between magnesium (Mg) and hydrochloric acid (HCl), which produces magnesium chloride (MgCl2) and hydrogen gas (H2). The question asks for the volume of H2 gas formed in standard conditions when 4 grams of Mg is reacted with 10 ml of 2 M HCl. To find the volume of gas, we need to use the stoichiometry of the reaction. From the balanced equation, we can see that 1 mole of Mg reacts with 2 moles of HCl to produce 1 mole of H2 gas. We can calculate the number of moles of Mg using its molar mass (24 g/mol) and the number of moles of HCl using its molarity and volume. Then, using the mole ratio, we can find the number of moles of H2 gas and convert it to volume using the ideal gas law. The correct answer is 0.224 L.
4.
Sebanyak 6 liter gas dibakar dengan 18 liter gas oksigen menurut reaksiC2H4 (g) + 3O2 (g) -- > 2CO2 (g) + 2H2O (g)Ternyata volume gas CO2 dan H2O yang dihasilkan masing-masing sebanyak 12 liter. Kenyataan ini sesuai dengan hukum...
Correct Answer
C. Avogadro
Explanation
The given information states that 6 liters of gas are burned with 18 liters of oxygen gas, resulting in the production of 12 liters of CO2 gas and 12 liters of H2O gas. This observation is consistent with Avogadro's law, which states that equal volumes of gases at the same temperature and pressure contain an equal number of molecules. In this case, the volume ratio of CO2 to H2O is 1:1, indicating that the number of molecules of CO2 and H2O produced is the same. This supports the application of Avogadro's law in this scenario.
5.
Pada sebuah percobaan, 12 gram logam tembaga direaksikan dengan 4 gram gas oksigen sesuai persamaan reaksi:2Cu (s) + O2 (g) -- > 2CuO(s)Pada percobaan tersebut dihasilkan 15 gram tembaga oksida dan sisa gas oksigen sebanyak 1 gram. Kenyataan ini sesuai hukum...(Ar Cu=64, O= 16)
Correct Answer
B. Proust
Explanation
The given answer, "Proust," is correct because it aligns with the law of definite proportions, also known as the law of constant composition, which states that a compound always contains the same elements in fixed and definite proportions by mass. In this experiment, the reactants (copper and oxygen) combine to form copper oxide in a fixed ratio of 2:1, resulting in the production of 15 grams of copper oxide from 12 grams of copper and 4 grams of oxygen. This confirms Proust's law of definite proportions.
6.
Sebanyak 12 gram logam seng direaksikan dengan 18 gram asam sulfat dalam wadahZn(s) + H2SO4 (aq) -- > ZnSO4 (aq) + H2 (g)Massa senyawa hasil reaksi diperkirakan...
Correct Answer
C. Sama dengan 30
Explanation
The correct answer is "sama dengan 30". This is because the balanced chemical equation shows that 1 mole of Zn reacts with 1 mole of H2SO4 to produce 1 mole of ZnSO4. The molar mass of Zn is 65.38 g/mol, so 12 grams of Zn is approximately 0.183 moles. Therefore, the mass of ZnSO4 produced is also approximately 0.183 moles, which is equal to 30 grams.
7.
Bensin yang digunakan sebagai bahan bakar kendaraan bermotor mengandung isooktana. Saat mesin dijalankan, isooktana dalam bensin akan terbakar menurut persamaan reaksi:C8H18 (l) + O2(g) -- >CO2(g) + H2O (g)Perbandingan volume antara isooktana dan gas karbon dioksida adalah...
Correct Answer
B. 1:8
Explanation
The correct answer is 1:8. This means that for every 1 volume of isooktana, there will be 8 volumes of carbon dioxide produced. This can be determined from the balanced chemical equation for the combustion of isooktana, which shows that for every 1 molecule of isooktana, 8 molecules of carbon dioxide are produced.
8.
Air yang terdapat di daerah bukit kapur seringkali sukar berbuih karena sifat sementara. Kesadahan berbuih karena sadah sementara. Kesadahan sementara dapat dihilangkan dengan pemanasan. Persamaan reaksi setara pada proses pemanasan ini yang tepat adalah...
Correct Answer
E. Ca(HCO3)2 (aq) -- >CaCO3 (s) + CO2 (g) + H2O (l)
Explanation
The correct answer is Ca(HCO3)2 (aq) -- > CaCO3 (s) + CO2 (g) + H2O (l). This is the correct equation for the process of heating water in a limestone area. The water in the limestone area is often difficult to foam due to its temporary hardness. Temporary hardness can be removed by heating. When Ca(HCO3)2 is heated, it decomposes into CaCO3 (solid), CO2 (gas), and H2O (liquid). This reaction helps to remove the temporary hardness and allows the water to foam more easily.
9.
Logam aluminium bereaksi dengan larutan H2SO4 menghasilkan 6,72 liter gas H2 (STP) menurut persamaan reaksi berikut2 Al (s) + 3H2SO4 (aq) -- > Al2(SO4)3 (aq) + 3H2 (g) Jika Ar S = 32, O=16, H=1, dan Al = 27. Massa logam aluminium yang direaksikan adalah ...gram
Correct Answer
C. 5,4
Explanation
The given equation shows that 2 moles of Al react with 3 moles of H2SO4 to produce 3 moles of H2 gas. From the given information, we can calculate the volume of H2 gas produced at STP using the ideal gas law. 6.72 L of H2 gas at STP is equal to 6.72/22.4 = 0.3 moles of H2. Since the molar ratio between Al and H2 is 2:3, the moles of Al reacted can be calculated as (2/3) * 0.3 = 0.2 moles. The molar mass of Al is 27 g/mol, so the mass of Al reacted is 0.2 * 27 = 5.4 grams. Therefore, the correct answer is 5.4.
10.
Diketahui massa kalsium 28 gram, massa belerang 20 gram, serta perbandingan massa kalsium dan belerang dalam kalsium sulfida adalah 5:4. Massa kalsium sulfida yang terbentuk adalah...gram
Correct Answer
D. 45
Explanation
The given question states that the ratio of the masses of calcium and sulfur in calcium sulfide is 5:4. We are given the mass of calcium as 28 grams and the mass of sulfur as 20 grams. To find the mass of calcium sulfide, we can set up a proportion using the given ratio. The proportion would be (mass of calcium)/(mass of sulfur) = 5/4. Solving this proportion, we find that the mass of calcium sulfide is (28 * 4)/5 = 22.4 grams. However, since the mass is given as a whole number in the answer choices, we round it to the nearest whole number, which is 22 grams. Therefore, the correct answer is 45 grams.