# Chemistry

posted by .

You find a compound composed only of element x and hydrogen,and know that it is 91.33% element x by mass. Each molecule has 2.67 times as many H atoms as x atoms. What is element x ?

• Chemistry -

Take a 100 g sample. That will consist of
91.33 g element X and
8.67 g H. Convert to moles.

91.33/atomic mass X = moles X = (91.33/z) which I am calling the atomic mass z = moles element X. We also know that there are 2.67 x as many x atoms as there are H atoms.
8.67 g H/1 = 8.67 moles H.

So the empirical formula is
X(91.33/z)H8.67 + we know about the 2.67 so I set
2.67*91.33/z = 8.67 and solve for z.
If I didn't goof, I found z = 28.1 which probably is Si. Then
Si = 91.33/28 = 3.26
H = 8.67/1 = 8.67

Find the ratio and round to whole numbers. The easy way to do this is to divide the smallest number by itself (thus 1.00 for that one) and divide the other number of the same small number.
8.67/3.26 = 2.65. Now multiply each by whole numbers until you get two numbers close enough to round to whole numbers. I think a multiplier of 3 will do it.

## Similar Questions

1. ### science

How do you find out the number of atoms in a chemical formula?
2. ### Biology

4. The difference between an atom and and element is a. an element is made of atoms b. atoms are made of elements c. atoms are held together by covalent bonds d. none of the above C?
3. ### Biology

4. The difference between an atom and and element is a. an element is made of atoms b. atoms are made of elements c. atoms are held together by covalent bonds d. none of the above C?
4. ### biology

1 mole of an element or compound contains 6.20 times 10 to the 23rd power atoms or molecules of the element or compound. 1 mole of an element or compound has a mass equal to its mass number (or molecular weight) in grams. For example, …
5. ### chemistry

The chemical substance in natural gas is a compound called methane. Its molecules are composed of carbon and hydrogen and each molecule contains four atoms of hydrogen and one atom of carbon. In this compound, 0.33597g of hydrogen …
6. ### chemistry

Isotopes (select one or more): are chemicals that react only with protons. for an element have the same chemical properties. are atoms of an element that differ in the number of protons. are atoms of an element that differ in the number …