Question

Chemistry help please! I just need to make sure the answers correct.... Thank you!

1. In a reaction between vinegar and antacid tablets, the antacid is the limiting reagent. At constant pressure and temperature, three tablets produce 600 cm3 of gas. What volume will two tablets produce?
A. 400 cm3
B. 600 cm3
C. 800 cm3
D. 1,200 cm3
------ my answer is A. 400 cm3

2. You breathe in 3.0 L of pure oxygen at 298 K and 1,000 kPa. How many moles of oxygen did you take in?
A. 0.05 moles
B. 1.21 moles
C. 2.42 moles
D. 20.0 moles
------- My answer is B 1.21 moles,

Answer 1

1. At constant tempaerature and pressure, 3 tablets produce 600cm^3 of gas
Thus calculating for 1 tablet that produces 600 / 3 = 200 cm^3
So now two tablets produce 200 x 2 = 400 cm^3
2. We have the equation PV = nRT, n being the number of moles
Pressure P = 1,000 kPa
Volume V = 3 L
R = 8.31 L kPa/mol-K
Temperature T = 298 K
n = PV / RT = (1000 x 3) / (8.31 x 298) = 3000 / 2476.38 = 1.21 moles
Number of moles = 1.21 moles.