Questions in chemistry

Questions in chemistry

[Terjawab] When [tex]8.00 \times 10^{22}[/tex] molecules of ammonia react with [tex]7.00 \times 10^{22}[/tex] molecules of oxygen according to the chemical equation shown below, how many grams of nitrogen gas are produced? \[ 4\text{NH}_3(g) + 3\text{O}_2(g) \rightarrow 2\text{N}_2(g) + 6\text{H}_2\text{O}(g) \]

[Terjawab] 1. Compare the location of electrons in an atom based on Bohr's theory with the location of electrons in an atom based on the current atomic theory. 2. Rutherford performed his gold-foil experiment to test Thomson's plum-pudding model. Describe what the results would have looked like if it had supported the plum-pudding model instead of contradicting it. Please explain concisely.

[Terjawab] Pentane, C5H12, will react as shown below: C5H12(l) + O2 → CO2 + ____H2O 1. Balance the equation above by putting coefficients into each blank space. - Answer: 1C5H12 + 8O2 → 5CO2 + 6H2O 2. How many atoms of oxygen are in 144 grams of pentane? Step 1: 144 g of C5H12 × (1 mole / 72.17 g) = 1.995 moles of C5H12 Step 2: 1.995 moles of C5H12 × (8 moles of O2 / 1 mole of C5H12) = 15.962 moles of O2 Step 3: 15.962 moles of O2 × (6.02 × 10^23 atoms of O2 / 1 mole of O2) = 9.609 × 10^24 atoms of O2 3. How many atoms of oxygen are in 192 grams of carbon dioxide gas? Step 1: 192 grams of CO2 × (1 mole of CO2 / 44.01 grams of CO2) = 4.363 moles of CO2 Step 2: 4.363 moles of CO2 × (2 atoms of O / 1 mole of CO2) = 8.726 moles of O atoms Step 3: 8.726 moles of O atoms × (6.02 × 10^23 atoms / 1 mole) = 5.253 × 10^24 atoms of O 4. A) CIRCLE ONE: True or False: The reactant you begin with fewer grams of is your limiting reactant. B) If 32 g of oxygen gas and 32 g of pentane are combined, how much water will be produced, in moles? (Use your reaction from the top of the first page) Note: Review the calculations for accuracy and ensure the steps align with stoichiometric principles.

[Terjawab] What is the balanced chemical equation for caffeine?

[Terjawab] Why do the two elements, silver and iron, have different properties?

[Terjawab] What chemical compound is [tex]C_2H_5OH[/tex]?

[Terjawab] The chain on a bicycle rusts faster when the bicycle is left outside in damp conditions. Which of the following factors affect the rate at which the bicycle chain rusts? A. Surface area B. Concentration of oxygen atoms in air C. Temperature D. All of the above E. B and C F. A and C G. A and B

[Terjawab] Alexis was interested in the way mirrors reflect. The living room of Alexis' house had one big window in the front, and a very large mirror on the back wall. Alexis hypothesized that the room would heat up faster in the morning with the mirror on the wall than it would if the mirror were covered with a sheet that was the same color as the walls. What will make Alexis' hypothesis valuable? A. It cannot be valuable because the investigation is in her house and not in the science lab. B. Any testable hypothesis is valuable. C. It will be valuable only if it is proved incorrect. D. It will be valuable only if it is proved correct.

[Terjawab] Enzymes increase the rate of a reaction by __________? A. Contributing water to the reaction. B. Contributing electrons to the reaction. C. Changing the pH of the substrates. D. Decreasing activation energy. E. Increasing the temperature of the substrates.

[Terjawab] A solution tested in the laboratory shows a pH of 14. Which of the following statements best describes this solution? A. It is a highly acidic solution with a high hydrogen ion concentration. B. It is a highly alkaline solution with a high hydrogen ion concentration. C. It is a highly basic solution with a high hydrogen ion concentration.