14) At which temperature can water contain the most dissolved oxygen at a pressure of 1 atmosphere?
(A) 10.°C
(C) 30.°C
(B) 20.°C
(D) 40.°C

A. 10 C

Explanation:

In cold water, intermolecular forces between oxygen and hydrogen are stronger and greater. So solubility of oxygen is higher in water with lowest temperature.

given:

mass of na = 115 g

excess cl2

to determine:

mass of nacl produced

explanation:

given reaction is-

2na(s) + cl2(g) → 2nacl(s)

since cl2 is in excess, na will be the limiting reagent

as per the reaction stoichiometry na: nacl = 1: 1

i.e. moles of na reacted = moles of nacl formed

now, # moles of na = mass of na/atomic mass

                                  = 115 g/23 g.mol-1 = 5 moles

therefore, moles of nacl = 5

molar mass of nacl = 58 g/mol

mass of nacl = 5 moles * 58 g.mol-1 = 290 g

ans: amount of nacl produced = 290 g

1.solid

2.carbon dioxide

3.helium