It is necessary to solve the problem in chemistry The element forms a compound with a hydrogen of the RH4 type.
It is necessary to solve the problem in chemistry The element forms a compound with a hydrogen of the RH4 type. The relative molecular weight of its oxide is 60. Define the element. Write down the formulas of its higher oxide and hydroxide.
Given:
RH4 – element hydride
Mr (RO) = 60
To find:
R -?
RO -?
R (OH) -?
Decision:
1) Find the relative atomic mass of an element:
Ar (R) = (Mr (RO) – Ar (O) * x) / y, where (x) is the number of O atoms in the oxide, and (y) is the number of R atoms. Then
Ar (R) = (60 – 16 * 1) / 1 = 44 – there is no such element;
Ar (R) = (60 – 16 * 1) / 2 = 22 – there is no such element;
Ar (R) = (60 – 16 * 2) / 1 = 28 – silicon (Si);
2) Write down the formulas of higher oxide and silicon hydroxide:
Since silicon has a maximum valence IV, then
SiO2 and Si (OH) 4.
Answer: The unknown element is silicon (Si); higher oxide – SiO2; higher hydroxide – Si (OH) 4.