A sample of air has a volume of 140 mL 0.980 atm. At what pressure will its final volume be 50.0 mL at constant temperature?

The new pressure is 2, 74 atm

Explanation:

We apply Boyle Mariotte's law, where for a given mass of gas at constant temperature, the pressure and volume vary inversely proportionally:        P1xV1 = P2xV2  P2=( P1 x V1)/V2     1 L1000L--->( 140ml/1000ml)x1L=0,140 L

(50ml/1000ml)x 1L =0,050L

P2= (0,980 atm x 0,140 L)/0,050L= 2, 744 atm

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