Include explanations please 1) A certain gas effuses through a pinhole one-half
ID: 862561 • Letter: I
Question
Include explanations please
1) A certain gas effuses through a pinhole one-half as fast as gaseous oxygen does. The molecular weight of the unknown gas must be (in g/mol):
a) 8
b) 16
c) 64
d) 128
e) impossible to determine
2) Which of these will produce an acidic solution when dissolved in water?
a) NaCl
b) Na2O
c) NH3
d) NO2
e) KBr
3) An ice cube with a mass of 30.0 grams is removed from a freezer. The ice cube is initially already at its melting temperature. How much heat (in kJ) is absorbed for the ice cube to melt and the resulting water to warm to a room temperature of 25.0C? (Note: heat of fusion of ice = 6.01 kJ/mole, heat of vaporization of water = 40.7 kJ/mole, and specific heat of water = 4.18 J/g*C)
a) 3.14
b) 10.0
c) 13.2
d) 68.0
e) 81.2
4) A 325 mL sample of hydrochloric acid was treated with excess zinc, producing 6.254 L of dry hydrogen gas at 24C and 750 mmHg. Calculate the original concentration of the acid.
a) 0.389 M
b) 0.778M
c) 1.25M
d) 1.56M
e) 1.98M
Explanation / Answer
1) C
2) D
3) B
4) A