A 25.0-g sample of barium reacted completely with water. What is the equation for the reaction? How many milliliters of dry H2 evolved from 21C and 748mmHg?

Question

Chemistry

Adrienne Holland

28 May, 22:42

A 25.0-g sample of barium reacted completely with water. What is the equation for the reaction? How many milliliters of dry H2 evolved from 21C and 748mmHg?

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Tony Doyle · Answer 1

Ba+H↓2O⇒BaO+H↓2O

You'll have to divide 25.0g by the formula mass of barium and then compare the mole ratio in your formula.

PV=nRT Rearranged is: V=nRT/P

V=volume=? n=moles of H2 P=pressure 748mmhg

R=universal gas constant (62.3638L*mmHg/K*mol)

T = temperature (21+273.15=) 294.15K

L=1000ml

25.0g divided by 137.3g (formula mass of barium) = moles for barium

1 mole of barium = 1 mole of H2

H2 moles times 62.3638 L*mmHg/K*mol (these cancel out to L) times 294.15K over 748mmHg

Divide your answer which should be in L to ml by multiplying it by 1000.

(25/137.3) (62.3638*294.15) / 748=answer*1000

I got 4.47x10∧3 but depending on how your teacher calls each number significant change your sig figs to the lowest number. Should look pretty similar. Good luck!