Answer:
X is calcium with the symbol Ca
Explanation:
From the first statement:
X reacted with H2 to produce Z i.e
X + H2 —> Y
Y is heated to form X and H2 i.e
Y —> X + H2
Let us obtain moles of H2 produced. This is illustrated below:
Volume of H2 produced = 559 mL = 0.559 L.
I mole of H2 occupy 22.4L at stp
Therefore, b mol of H2 will occupy 0.559 L at stp i.e
b mol of H2 = 0.559/22.4
b mol of H2 = 0.025 mole
Next 0.025 mole of H2 to gram..
Molar Mass of H2 = 2x1 = 2g/mol
Mole of H2 = 0.025 mole
Mass = number of mole x molar Mass
Mass of H2 = 0.025 x 2
Mass of H2 = 0.05g
From the question given, we were told that 1g of X reacted. This means that 1g of X reacted with 0.05g of H2. Now let us determine the mass of X that will react with 1 mol ( i.e 2g) of H2. This is illustrated below:
From the reaction,
It was discovered that 1g of X reacted with 0.05g of H2.
Therefore, P g of X will react with 2g of H2 i.e
P g of X = 2/0.05 = 40g/mol
The molar mass of X is 40g/mol.
Now let us consider the second statement to see if we'll obtained the same result as 40g/mol of X
From the second statement:
X also combines with chlorine to form a compound Z, which contains 63.89 percent by mass of chlorine i.e
X + Cl2 —> Z
Molar Mass of Z (X + 2Cl) = X + (35.5 x 2) = X + 71.
Z contains 63.89% by mass of Cl2.
We can obtain the molar mass of X as follow:
Percentage by mass of Cl2 in the compound Z is given by:
Mass of Cl2/Molar Mass x100
63.89/100 = 71/(X + 71)
Cross multiply to express in linear form
63.89(X + 71) = 100 x 71
Clear the bracket
63.89X + 4536.19 = 7100
Collect like terms
63.89X = 7100 - 4536.19
63.89X = 2563.81
Divide both side by 63.89
X = 2563.81/63.89
X = 40g/mol
Now we can see that in both experiments, the molar mass of X is 40g/mol.
Comparing the value of X i.e 40g/mol with that from the periodic table, X is calcium with the symbol Ca
