A sample of hydrogen effuses through a porous container about 9 times faster than an unknown gas. Calculate the molar mass of the unknown gas.

2.  . A solution is prepared by adding 25.0 mL of 1.30 M AlCl3 solution to a flask, and then adding enough water to give a final volume of 200.0 mL. What is the molarity of the solution? 

 

3. 25.00 g of potassium chloride (KCl) is dissolved in enough water to make 250.0 mL of a solution with a density of 1.14 g/mL. What is the concentration of the solution in: 

(a) % (m/m) 

(b) % (m/V) 

(c) molarity?

4. Xylene glycol, the major ingredient in antifreeze, freezes at -11.5 °C. What is the freezing point in 

(a) K 

(b) °F?

5. What is the normal boiling point of a 2.70 M solution of KBr that has a density of 1.80 g/ml?(KB for H2O is 0.512 °C .kg/mole)

6. How many milliliters of 3.0 M H2SO4 are needed to make 450 mL of 0.10 M H2SO4? 

7. What is the rate of reaction if the concentration of the product increases from 0.5 M to 1.5 M in 5 minutes? 

8. In reference to the above reaction: If more NH3 is added to the following system at equilibrium, how will the equilibrium shift? 

i. Left 

ii. Right

iii. No shift

b. If the following reaction at 698 K has equilibrium concentration values of 0.584 M HI, 0.0793 M H2, and 0.0793 M I2, what is the value of the equilibrium constant? 

                                                     2HI → H2 (g) + I2 (g)

3. In one trial for inelastic collisions in the experiment, cart I has mass m, and is initially moving with velocity to the right. Cart 2 with mass m, is initially moving with velocity also to the right. The velocity of the cart 1 is larger than the velocity of cart 2 causing a collision between both carts. After the collision, the carts stick together and move with velocity to the right. a) Write down the expression for the magnitude of linear momentum of the system before collision. b) Write down the expression for the magnitude of linear momentum of the system after the collision. c) Write down the expression for the magnitude of kinetic energy of the system before collision. d) Write down the expression for the magnitude of the kinetic energy of the system after the collision.