a sample of cabr2 and nabr contains 2.4×10^23 atoms of ca and 6.6×10^23 atoms of br. mass of nabr in the given sample is please answer correctly otherwise i will report you
Answers
Given info : A sample of CaBr₂ and NaBr contains 2.4 × 10²³ atoms of Ca and 6.6 × 10²³ atoms of Br.
To find : the mass of NaBr is ...
solution : A sample of CaBr₂ and NaBr contains 2.4 × 10²³ atoms of Ca and 6.6 × 10²³ atoms of Br.
no of Br atoms = 6.6 × 10²³
no of moles of Br atoms = no of Br atoms/Avogadro's number
= 6.6 × 10²³/6 × 10²³
= 1.1
no of Ca atoms = 2.4 × 10²³
no of moles of Ca atoms = 2.4 × 10²³/6 × 10²³
= 0.4
we see, there are two atoms of Br and one atom of Ca in one molecule of CaBr₂.
so no of moles of Br in CaBr₂ = 2 × no of moles of CaBr₂
= 2 × 0.4 = 0.8
∴ no of moles of Br in NaBr = 1.1 - 0.8 = 0.3
mass of NaBr = no of moles of NaBr × molar mass of NaBr
= 0.3 × 103 = 30.9 g
therefore the mass of NaBr in the sample is 30.9 g.