Ideal Gas Laws, Gas Mixtures and KMT

Version 001 – HW04-Ideal Gas Laws, Gas Mixtures and KMT – sparks – (52100) 1 This print-out should have 15 questions. Multiple-choice questions may continue on the next column or page – ﬁnd all choices before answering. Holt da 11 review 22 001 10.0 points One method of estimating the temperature of the center of the sun is based on the assump- tion that the center consists of gases that have an average molar mass of 2.00 g/mol. If the density of the center of the sun is 1.40 g/cm 3 at a pressure of 1.30 × 10 9 atm, calculate the temperature. Correct answer: 2.26205 × 10 7 ◦ C. Explanation: d =1.4g/cm 3 P =1.3 × 10 9 atm M =2.00 g/mol T =? M = d · R · T P T = MP dR = (2.00 g/mol) ( 1.3 × 10 9 atm ) (1.4g/cm 3 ) ( 0.0821 L·atm mol·K ) × 1 mL 1 cm 3 × 1L 1000 mL =2.26205 × 10 7 ◦ C ChemPrin3e 04 42 002 10.0 points The analysis of a hydrocarbon revealed that it was 85.6281% C and 14.3719% H by mass. When 1.51 g of the gas was stored in a 1 L ﬂask at -128.97 ◦ C, it exerted a pressure of 484 Torr. What is the molecular formula of the hydrocarbon? 1. C 3 H 8 2. C 2 H 4 correct 3. C 7 H 14 4. C 4 H 10 5. C 4 H 6 6. C 3 H 5 7. C 5 H 10 8. C 6 H 12 9. C 8 H 16 Explanation: m=1.51 g V =1L T = 144.18 K P = 484 Torr R =0.08206 L · atm/K/mol The empirical formula derived from the el- emental analyses is (CH 2 ) n . Applying the ideal gas law, PV = nRT = m MW RT MW = m TR PV = (1.51 g) (144.18 K) (484 Torr) (1 L) 760 Torr 1 atm × 0.08206 L · atm/K/mol = 28.0532 g/mol . The empirical formula mass is 14.0266 g/mol. The value of n in the formula (CH 2 ) n is, therefore, equal to 2. Brodbelt 12 04a 003 10.0 points For the reaction 2 HCl + Na 2 CO 3 → 2 NaCl + H 2 O + CO 2 179.2 liters of CO 2 is collected at STP. How many moles of NaCl are also formed? 1. 4.0 moles 2. 8.0 moles 3. 12.5 moles 4. 6.0 moles 5. 32.0 moles

Ideal Gas Laws, Gas Mixtures and KMT

Documents

ideal gas law

law

boyles law

ideal gases

gas law

gass pressure

gas

chemistry