Answer:
.371 mole of NaCl
Explanation:
Na Cl Mole weight = 22.989 + 35.45 = 58.439 g/mole
21.7 g / 58.439 g/mole = .371 mole
Answer: Number of molecules of hydrogen gas 
Explanation:

Number of moles of sodium =
According to reaction , 2 moles of sodium produces 1 mole of hydrogen gas , then 2.11 mol of sodium will=
of hydrogen gas that is 1.05 moles of hydrogen gas.
Number of molecules =
moles of substance
Moles of hydrogen gas formed = 1.05 moles
Number of molecules of hydrogen gas =
moles of hydrogen gas
Number of molecules of hydrogen gas 
Answer:
2 hours Speed =110/2=55 miles ler hour
C (667) that’s the answer boiii
Answer:
John Dalton's Atomic Model Below ⬇
Explanation: