Stioichiometry

Q: What energy would a proton of light have at wavelength 3x10-5 cm?

(a) :  2.64x10-36
(b) :  6.6x10-27
(c) :  2.2x10 -31
(d) :  6.6x10-31
(e) :  None of the Above
Answer:  6.6x10-31
Explanation:  hv/ɻ=(6.6x10-34Js)(3x108m/s)/3x10-3 m=6.6x10-31

Q: Which of the following contains the same number of molecules as 9 g of water?

(a) :  2 g of hydrogen gas
(b) :  14 g of nitrogen
(c) :  32 g of oxygen gas
(d) :  44 g of carbon dioxide
(e) :  None of the Above
Answer:  14 g of nitrogen
Explanation:  One mole of substance contains 6 x 10 23 particles, 9 g of water is equivalent to 0.5 mol of water.Since 14 g of N₂(Mr=28) contains 0.5 mole, the number of molecules should be the same i.e 0.5 x 6 x 10 23 molecules.

Q: 6 g of hydrogen gas is:

(a) :  4 mol
(b) :  1 mol
(c) :  3 mol
(d) :  2 mol
(e) :  None of the Above
Answer:  3 mol
Explanation:  

Q: If 20 ml of 0.5 M salt solution is diluted to 1 liter, what is the new concentration?

(a) :  0.01M
(b) :  10M
(c) :  0.001M
(d) :  5M
(e) :  None of the Above
Answer:  0.01M
Explanation:  MAVA=MBVB ,MB=MAVA/VB,MB=0.5X20ml/1000ml=0.01M

Register now to view all Question's

Sign in OR Sign Up


Back to top