Answer:
Explanation:
mass of one virus = 9.0 x 10⁻¹² mg
mass of one mole = 6.02 x 10²³ x mass of one virus
= 6.02 x 10²³ x 9.0 x 10⁻¹²
= 54.18 x 10¹¹ mg
= 54 x 10⁸ g .
= 54 x 10⁵ kg .
b )
let n be no of moles of virus that will be equal to weight of oil tanker
n x 54 x 10⁵ = 3 x 10⁷
n = 5.5555
rounding off to 2 significant figure
5.6 moles Ans .
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When something changes state.
For example solid to a liquid
Liquid to a gas
Answer:
0.6 moles of CaO will produced.
Explanation:
Given data:
Mass of calcium = 23.9 g
Moles of CaO produced = ?
Solution:
Chemical equation:
2Ca + O₂ → 2CaO
Number of moles of calcium:
Number of moles = mass/ molar mass
Number of moles = 23.9 g / 40 g/mol
Number of moles = 0.6 mol
Now we will compare the moles of calcium and CaO.
Ca : CaO
2 : 2
0.6 : 0.6
0.6 moles of CaO will produced.
