Question

Question time :


1. Calculate the mass of :


i) 1 molecule of O2


ii) 1 molecule of H2O

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2. Calculate no. of moles and number of molecules in following masses.

i) 4 g of O2

ii) 11 g of Co2


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Full explanation please!
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Answer 1

Explanation:

RuDeBoy

❤.Oxygen's atomic weight is 16.00 amu. 1 mole of oxygen is 6.02 x 1023 atoms of oxygen 1 amu = 1.661 x 10-24g What is the molar mass (g/mole) of oxygen? Molar mass (in grams) is always equal to the atomic weight of the atom!

❤.The average mass of one H2O molecule is 18.02 amu. The number of atoms is an exact number, the number of mole is an exact number; they do not affect the number of significant figures. The average mass of one mole of H2O is 18.02 grams. This is stated: the molar mass of water is 18.02 g/mol.

❤.To calculate the number of molecules in 4g of oxygen, we have, Moles of oxygen = 4/32 = 0.125mol, Molecules of oxygen = 0.125 * 6.022 * 10^23 = 7.52 * 10^22. 6.02 x 1023 atoms of oxygen 1 amu = 1.661 x 10-24g.

❤.Given mass w= 11g. Molar mass of CO2= 12+2×16 =44. Now no of mole =w/m = 11/44 =1/4 = 0.25 mole Ans. 4.6.

✌Hope it helps u✌

Answer 2

Explanation:

see the attachment for answers