Question

Na Ulf 1) Solid sodium metal reacts with water to form sodium hydroxide and hydrogen gas. a. Write a balanced chemical equation for this reaction (2 pts) Nars) + H₂O → Na DH+H Nais) + H₂O11 - Na Oltiag) + Hig) b. How many grams of sodium metal were reacted with excess water if the hydrogen gas is collected over water at 23 °C in a 200 mL vessel and the total pressure in the vessel was 771 mmHg? (Epts) Protal =771 P. Ptotal 771 niming

Answer 1

answer:-

a)- balanced chemical equation

2Na(s) + 2H₂O → 2NaOH(aq) + H₂(g)

b)- given

first convert pressure mmHg to atm , so P= 771 mmHg that is P = 1.01447 atm

V = 200.0 mL tha is 0.200 L , T= 23 +273 = 296K R = 0.0821 L atm mol^-1K^-1

from the formula PV =n RT

n = PV/RT

n = 1.01447 x 0.200 /0.0821 x 296

n= 0.00835 that is n = 8.35 x 10^-3 moles

now we know that n = w/m so for calculating w = n x m

where m = mass of sodium which is 23 and also  there are 2 equiv of sodium metal...

so w = 2 x 23 x 8.35 x 10^-3 gm

w = 384.1 x 10^-3 w = 0.384 gm ( sodium metal react)