Which force prevents protons from repelling each other inside a nucleus?
the gravitational force
the weak nuclear force
the electromagnetic force
<u>the strong nuclear force</u>
Stoichiometry:
First, calculate the number of grams for one mole of Ca3 (PO3)4
(3 * (Mass of Ca)) + (4 * (Mass of P + (3 * Mass of Oxygen)))
= (3*40.08) + 4(30.97 + (3*16.00))
=(120.24) + 4(78.97)
=436.12 g / mol Ca3(PO3)4
This means there are 436.12 g per 1 mole of Ca(PO3)4. Since there are 4.50 moles of Calcium Phosphate, mulitply the molar mass of Ca(PO3)4 by 4.50 and you should get 1962.54 g. Since there are 3 sigfigs, the final answer is 1960 g.
on a side note: I put in all my work in case 1. your periodic table if different, 2. my work is wrong, 3. you put in the question wrong because I feel that the actual compound would be Ca3(PO4)3 instead of Ca3(PO3)4 (if this is the case, the answer should be 1820 g).
Metalloids:alloys of metallods are commonly used in discs like compact discs, CDs ,and DVDs .These materials change from glassy to crystalline with the application of heat which makes them useful as data storage media
The percentages are given in weight. You need to transform them into moles.
Take a basis of 100 grams of compound. Then there are 69.94 grams of iron and 30.06 grams of oxygen.
Use the atomic masses of iron and oxygen to obtain each number of moles.
Molar mass of iron: 55.85 g/mol
# moles of iron = 69.94 g / 55.85 g/mol = 1.252
Molar mass of oxygen: 16 g/mol
# moles of oxygen = 30.06 g / 16 g/mol =1.87875
Proportions
1.87875 moles of Oxigen/ 1.252moles of iron = 1.50 /1
3moles of Oxygen: 1 mol of Iron
Empirical formula: FeO3
Molar mass of the empirical formula: 55.85 g/mol + 3(16g/mol) = 103.85 g/mol
Molar mass of the compound / molar mass of the empirical formula = 199.55 g/mol / 103.85 g/mol = 1.92
Round to 2.
Then the molecular formula is the empirical formula times 2.
Fe2O6
