Chemistry homework help?

My homework is 10 questions. I would perfer to have this done as soon as possible and I will pay extra if it can be done in a short amount of time. This is online homework so I can let you know immediately if it is incorrect. Thanks alot.

1.   If a sample of LiNO₃ is found to contain 2.03 · 10¹⁸ N atoms how many moles of O atoms are present? Express your answer in scientific notation.

2.   If a sample of CO is found to contain 2.78 · 10¹⁸ O atoms how many CO molecules are present? Express your answer in scientific notation.

3.   How many C atoms are present in 0.902 g of C₂H₄ molecules? Express your answer in scientific notation.

4.   How many moles of Co atoms are present in 5.91 · 10¹⁹ Co[P(CH₃)₃]₄ molecules? Express your answer in scientific notation.

5.   How many moles of O atoms are present in 6.55 · 10²² F₂SO₂ molecules?

6.   If a sample of (NH₄)₂HPO₄ is found to contain 2.85 · 10^-3 g of P atoms how many (NH₄)₂HPO₄ formula units are present? Express your answer in scientific notation.

7.   If 860 mL of 0.0129 M aqueous Ba²⁺ and 430 mL of 0.0488 M aqueous HClO₄ are reacted, how many mol of liquid H₂O is produced?

Ba(OH)₂(aq) + 2 HClO₄(aq) → Ba(ClO₄)₂(aq) + 2 H₂O(l)

8.   If 890. mL of 0.07384 M aqueous NaI and 810. mL of 0.07654 M aqueous NO₃^- are reacted stoichiometrically according to the equation, how many mol of NaI remained?

Pb(NO₃)₂(aq) + 2 NaI(aq) → PbI₂(s) + 2 NaNO₃(aq)

9.   If 590 mL of 0.0847 M aqueous H₂SO₄ and 390 mL of 0.295 M aqueous OH^- are reacted, what mass (g) of liquid H₂O is produced.

H₂SO₄(aq) + 2 NaOH(aq) → Na₂SO₄(aq) + 2 H₂O(l)

10.   If 900. mL of 0.04444 M aqueous HClO₄ and 740. mL of 0.02919 M aqueous Ba²⁺ are reacted stoichiometrically according to the equation, how many mol of HClO₄ remained?

Ba(OH)₂(aq) + 2 HClO₄(aq) → Ba(ClO₄)₂(aq) + 2 H₂O(l)