Willsomeone, please check my answers? (<-----) indicates my answer.
1.A student increases the temperature of a 556 cm³ balloon from 278 K to 308 K. Assuming constant pressure, what should the new volume of the balloon be?
320 cm3
501 cm3
1232 cm3
616 cm3<------
2. Which of the following is true about a carbonated soft drink?
The carbon dioxide is the solvent, and water is the solute.
The water is the solvent, and the carbon dioxide is the solute.<----
The water is the solution, and carbon dioxide is the solvent.
The carbon dioxide is the solution, and the water is the solvent.
3. For the reaction CH3COOH CH3COO + H+, which of the following statements is true?
CH3COO is an Arrhenius base.
CH3COO is a conjugate base.<----
CH3COO is a Brønsted-Lowry acid.
CH3COOH is a Brønsted-Lowry base.
4. Which of the following is an exothermic reaction?
dissolving ammonium nitrate in water<---
melting ice
dissolving sugar in water
condensing steam
5. Of the metals Pb, Hg, Na, and Mg, which will not spontaneously donate electrons to copper in solution?
Pb
Hg<---
Na
Mg
6. The diagram is an example of which of the following?
(The element Butane is shown)
aldehyde
alkene
alkyne
alkane<-----
7. In the diagram, which part is negatively charged?
(A voltaic cell is shown)
wire
salt bridge
solid Zn
solid Cu<----
8. Which of the following functional groups defines a carboxylic acid?
COOH<----
=O
PO4
OH
9. Which of the following is a strong base?
ethyl alcohol
vinegar
ammonia
potassium hydroxide<----
10. How many moles of a gas sample are in a 10.0 L container at 373 K and 203 kPa? The gas constant is 8.31 L-kPa/mol-K.
0.33 moles
0.65 moles<---
1.11 moles
3.05 moles
11. You dissolve 0.37 g of potassium chloride (KCl) in 500 mL of water. What is the molarity of the solution? Use a periodic table.
0.5 M
0.1 M
0.05 M
0.01 M<-----
12. How much heat do you need to raise the temperature of 100 g of aluminum from 30°C to 150°C?
10.8 × 103 kJ
10.8 kJ
10.8 kJ
10.8 × 103 kJ<-----
13. If you have 10 grams of a substance that decays with a half-life of 14 days, then how much will you have after 70 days?
0.10 g
0.313 g<----
1.25 g
2.50 g
14. A solution has a hydrogen ion (or hydronium ion) concentration of 3.16 × 109 M. What is the pH of the solution?
8.5
8.0
8.0
8.5<----
15. Which of the following reactions occurs at the anode in a voltaic cell?
Mg (s) Mg2+ + 2e <------
K+ (aq) + e K (s)
Cd2+ (aq) + Zn (s) Zn2+ (aq) + Cd (s)
Cu2+ (aq) + 2e Cu (s)
# 4 is incorrect
# 7 is incorrect
# 9 is incorrect but if you go to k12 you'll get a B
I responded above.
Were these correct?
Wait so you got a lot of these right
Sure, I can check your answers for you. Here's the correct answer to each question and an explanation of how to arrive at that answer:
1. The question asks for the new volume of the balloon when the temperature is increased. We can use the ideal gas law equation, PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature. Since the pressure is constant, we can rearrange the equation to V₁/T₁ = V₂/T₂, where V₁ is the initial volume, T₁ is the initial temperature, V₂ is the final volume (what we're trying to find), and T₂ is the final temperature. Plugging in the values, we get (556 cm³)/(278 K) = V₂/(308 K). Solving for V₂ gives us V₂ = (556 cm³ * 308 K) / 278 K ≈ 616 cm³.
2. The question asks which of the following statements is true about a carbonated soft drink. In a carbonated soft drink, such as soda, the carbon dioxide gas dissolves in the water to form a solution. Therefore, the water is the solvent, and the carbon dioxide is the solute.
3. The reaction given is CH3COOH → CH3COO⁻ + H⁺. In this reaction, the CH3COO⁻ ion is formed by the loss of a proton (H⁺) from the CH3COOH molecule. The ion formed by the loss of a proton is called a conjugate base. Therefore, CH3COO is a conjugate base.
4. An exothermic reaction is a reaction that releases heat. Dissolving ammonium nitrate in water is an exothermic reaction because it releases heat. Therefore, the correct answer is dissolving ammonium nitrate in water.
5. Spontaneous electron donation refers to a metal donating electrons to another species without any external force applied. Among the metals Pb, Hg, Na, and Mg, Hg (mercury) will not spontaneously donate electrons to copper in solution. Therefore, Hg is the correct answer.
6. The diagram shows the element Butane. Butane is a hydrocarbon that contains only carbon and hydrogen atoms and has the molecular formula C4H10. It belongs to the class of organic compounds known as alkanes. Therefore, the correct answer is alkane.
7. In the voltaic cell diagram, the negatively charged part is the solid Cu electrode. In a voltaic cell, the anode is the electrode where oxidation occurs, and it is negatively charged. Therefore, the correct answer is solid Cu.
8. The functional group that defines a carboxylic acid is COOH. The COOH group consists of a carbonyl group (C=O) and a hydroxyl group (OH) attached to the same carbon atom. Therefore, COOH is the correct answer.
9. A strong base is a substance that can fully dissociate into hydroxide (OH⁻) ions in solution. Among the given options, potassium hydroxide (KOH) is a strong base because it fully dissociates into KO⁺ and OH⁻ ions in solution. Therefore, the correct answer is potassium hydroxide.
10. To find the number of moles of a gas sample in a container, we can use the ideal gas law equation, PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature. Rearranging the equation to solve for n gives us n = (PV)/(RT). Plugging in the values, we get n = (203 kPa * 10.0 L) / (8.31 L-kPa/mol-K * 373 K) ≈ 0.65 moles.
11. The molarity (M) of a solution is calculated by dividing the moles of solute by the volume of the solution in liters. In this case, we have 0.37 g of KCl as the solute and 500 mL (0.5 L) of water as the solvent. First, we need to convert grams to moles using the molar mass of KCl. The molar mass of KCl is approximately 74.55 g/mol. Therefore, the moles of KCl is (0.37 g) / (74.55 g/mol) ≈ 0.005 moles. Finally, dividing the moles by the volume gives us 0.005 moles / 0.5 L = 0.01 M.
12. The amount of heat required to raise the temperature of a substance can be calculated using the equation Q = mCΔT, where Q is the heat, m is the mass, C is the specific heat capacity, and ΔT is the change in temperature. In this case, we have 100 g of aluminum with a change in temperature of 150°C - 30°C = 120°C. The specific heat capacity of aluminum is approximately 0.897 J/g°C. Plugging in the values, we get Q = (100 g) * (0.897 J/g°C) * (120°C) = 10.8 × 10³ J (or 10.8 kJ).
13. The decay of a substance with a half-life can be calculated using the formula N = N₀ * (1/2)^(t/h), where N is the amount at a given time, N₀ is the initial amount, t is the time elapsed, and h is the half-life. In this case, we have 10 grams of a substance with a half-life of 14 days and we want to know the amount after 70 days. Plugging in the values, we get N = 10 g * (1/2)^(70/14) ≈ 0.313 g.
14. The pH of a solution can be calculated using the equation pH = -log[H⁺], where [H⁺] is the hydrogen ion concentration. In this case, we have an [H⁺] concentration of 3.16 × 10⁻⁹ M. Taking the negative logarithm, we get pH = -log(3.16 × 10⁻⁹) ≈ 8.5.
15. In a voltaic cell, the anode is the electrode where oxidation occurs. Among the given reactions, Mg (s) → Mg2+ + 2e represents the oxidation of magnesium, where it loses two electrons. Therefore, the correct answer is Mg (s) → Mg2+ + 2e.