Science Homework Help

how many atoms are in:

6.0×10−3 mol C

29.9 molmol Hg

0.210 molmol Na

5.4×1024 PbPb atoms

3.77×1022 HeHe atoms

6.34×1023 KK atoms

4.86×1021 CaCa atoms

How many moles of atoms are in each elemental sample?

1.24 gg Zn

17.9 gg Ar

80.5 gg Ta

2.24×10−2 gg Li

What is the mass in grams of each elemental sample?

6.67 molmol W

0.589 molmol Ba

68.5 molmol Xe

1.58 molmol S

How many molecules are in each sample?

4.0 gg H2O

62.4 gg N2

81 gg CCl4

16 gg C6H12O6

Calculate the mass in grams of each sample.

5.44×1020 H2O2H2O2 molecules

4.0×1022 SO2SO2 molecules

6.0×1025 O3O3 molecules

9.90×1019 CH4CH4 molecules

Determine the number of moles of HH in each sample.

4.54 molmol H2O

8.64 mol NH3

0.107 molmol N2H4

36.0 molmol C10H22

Calculate the number of grams of sodium in 3.00 gg of each sodium-containing food additive.

NaClNaCl (table salt)

Na3PO4Na3PO4 (sodium phosphate)

NaC7H5O2NaC7H5O2 (sodium benzoate)

Na2C6H6O7Na2C6H6O7 (sodium hydrogen citrate)

Calculate the mass of silver chloride in grams required to make 5.6 gg of silver plating. Silver chloride, often used in silver plating, contains 75.27% AgAg.

Solid lead(II)(II) sulfide reacts with aqueous hydrochloric acid to form solid lead(II)(II) chloride and dihydrogen sulfide gas.Express your answer as a chemical equation. Identify all of the phases in your answer.

Gaseous carbon monoxide reacts with hydrogen gas to form gaseous methane (CH4)(CH4) and liquid water.

Solid iron(III)(III) oxide reacts with hydrogen gas to form solid iron and liquid water.

Gaseous ammonia (NH3)(NH3) reacts with gaseous oxygen to form gaseous nitrogen monoxide and gaseous water.

Solid copper reacts with solid sulfur to form solid copper(I) sulfide.

Write a balanced chemical equation for this reaction.

Chromium reacts with gaseous oxygen to form solid chromium (III)(III) oxide.

Balance each chemical equation.

N2H4(l)→NH3(g)+N2(g)

H2(g)+N2(g)→NH3(g)

Au2O(s)+C(s)→Au(s)+CO(g)

H2(g)+Br2(g)→HBr(g)

PbO2(s)+HCl(aq)→Cl2(g)+PbCl2(aq)+H2O(l)