Answer:
1368.9 [gr].
Step-by-step explanation:
1. the formula of the required mass is:
m=Mν, where M=[gr/mol] and ν=[moles];
2. M=M(NaCl)=M(Na)+M(Cl)=23+35.5=58.5 [gr/mol];
ν=23.4 [moles] according to the condition, then
3. the required mass:
m=23.4*58.5=1368.9 [gr].