At STP graphite and diamond are two solid forms of carbon which statement explains why these two forms of carbon differ in hardn
2 answers:
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Answer : The chemical symbol for this element is, (La)
Explanation : Given,
Mass of = 0.760 g
Mass of = 1.610 g
The given chemical reaction is:
First we have to calculate the moles of and
.
Molar mass of Cl = 35.5 g/mole
Let the molar mass of element 'X' be, M
and,
Molar mass of I = 126.9 g/mole
Let the molar mass of element 'X' be, M
From the balanced chemical reaction we conclude that,
The moles of ratio of and
is, 1 : 1
That means,
From this we conclude that the element (X) is lanthanum (La) that has molecular weight, 138.667 g/mol.
Hence, the chemical symbol for this element is, (La)
Answer:
2.85moles of oxygen gas
Explanation:
Given parameters:
Volume of oxygen gas = 63.8L
Unknown:
Number of moles = ?
Solution:
We assume that the gas is under standard temperature and pressure. To find the number of moles, use the expression below:
1 mole of a gas at STP occupies a volume of 22.4L
So;
63.8L of oxygen gas will take up a volume of
= 2.85moles of oxygen gas