Question
answer the question and number each one of them
Eye protection is needed in lab even if only one person is doing experimental work. (True/False) (5 points) 1. 2. Eating in lab is acceptable if no one is doing experimental work. (True/False) (5 points) 3. A MSDS (Material Safety Data Sheet) should be consulted (check anylall that apply; 5 points) In case of fire or explosion In the event of a spill All of the above 3. Short Answers: (5 points each) a. 1 mole of the hydrogen carbonate ion, HCO, will neutralizemole(s) of H b. How many moles of H' will 1 g of NaHCO, neutralize? c. As the rate of a reaction increases, the time for a given number of moles of a reactant to be consumed (increases; decreases, stays the same). The focus of an MSDS is on d. 4. During a titration of an acid with NaOH, 27.4 mL of a 0.117 M were required for neutralization. How many moles of NaOH were dispensed. (5 points) 5. Write the net ionic equations that explain the following observations: (5 points each) a. the dissolution of AgCI upon NH, addition. b. the neutralization of H' with OH
Explanation / Answer
1. TRUE
2. False. Not acceptabel to eat in the lab.
3. All the above
4.
(a) 1 mol of HCO3- will neutralise 1 mol of H+.
HCO3- (aq.) + H+ (aq.) --------------> H2O (l) + CO2 (g)
(b)
Mass of NaHCO3 = 1 g.
Molar mass of NaHCO3 = 23 + 1 + 12 + 48 = 84 g/mol
Moles of NaHCO3 = mass / molar mass = 1 / 84 = 0.0119 mol
NaHCO3 (aq.) + H+ (aq.) ------------> Na+ (aq.) + H2O (l) + CO2 (g)
1 mol of NaHCO3 needs 1 mol of H+
Then, 0.0119 mol of NaHCO3 needs 0.0119 mol of H+
(c) Decreases.
Because, rate is the number of moles reactant that changed per second.
5.
Moles of NaOH = Molarity * Volume in mL / 1000
n = 0.117 * 27.4 / 1000
n = 0.00320 mol