Answer:
Explanation:
Percent composition is percentage by the mass of element present in the compound.
The formula for chromium(III) nitrate is 
Molar mass of chromium(III) nitrate = 238.011 g/mol
1 mole of chromium(III) nitrate contains 9 moles of oxygen
Molar mass of oxygen = 16 g/mol
So, Mass= Molar mass*Moles = 16*9 g = 144 g
For the basic solution:
11.2 = -log[H+]
[H+] = 6.31 x 10⁻¹²
For the acidic solution:
2.4 = -log[H+]
[H+] = 3.98 x 10⁻³
The difference:
3.98 x 10⁻³ - 6.31 x 10⁻¹²
≈ 4.0 x 10⁻³
The answer is B
Answer:
this is the answer
I hope it helps you although
Hey there! The answer to your first question is SILICON, Nickle has 28 protons, silicon has 14, 14+14=28. Its the only element thats adds up. I dont know about the 2nd one myself.