Consider the following reaction to generate hydrogen gas: zn(s) + 2 hcl(aq) → zncl2(aq) + h2(g) the hydrogen gas is collected by displacement of water at 35.0 °c at a total pressure of 745 torr. the vapor pressure of water at 35.0 °c is 42 torr. calculate the partial pressure of h2 (in atm) if 353.2 ml of gas is collected over water from this method.

0.925 atm

Explanation:

By Dalton's Law, the total pressure of a gas mixture is the sum of the partial pressure of its components. The vapor pressure of the water is the pressure that some molecules that evaporated do under the liquid surface. The gas and the liquid are at equilibrium. So, the gas mixture is water vapor and hydrogen gas.

Ptotal = Pwater + PH₂

745 = 42 + PH₂

PH₂ = 703 torr

Transforming to atm:

1 atm 760 torr

x 703 torr

By a simple direct three rule

760x = 703

x = 0.925 atm

the correct answer is b. a strong acid completely dissociates to its ions when dissolved in water. completely dissociates to and ions. a is incorrect because does not fully ionize to and ions and some remain as the compound . c and d are incorrect because, and do not fall into the category of bronsted lowry acids. a bronsted lowry acid is a proton donor and since both molecules do not have a proton to donate they are not bronsted lowry acids. likewise,   if we use the lewis acid definition, they cannot be acids. a lewis acid is an electron pair acceptor. both and have a complete octet so can not accept any electrons which disqualifies them as acids.

the answer is d.) potassium