Unit 3 Chemistry

Molarity

100

how many grams are in 2.5 moles of carbon?

What is 25.02675g

200

how many atoms are in 2.1 moles of sulfur

What is 1.26462*10^23

300

25.0 g of carbon dioxide contains ___ oxygen atoms.

What is 6.80x10²³?

400

What mass of carbon is present in 1.4x10^20 molecules of sucrose (C12H22O11)?

MM=342 g/mol

What is 3.3x10^-2?

500

Which contains the least number of atoms?

a) 1.00 g C

b) 1.00 g O2

c) 1.00 g H2  

d) 1.00 g Fe

What is 1.00 g Fe (D)?

Empirical Formula

100

What is the molecular formula is hydrazine (empirical formula = NH₂), given its molecular mass of 32.0?

What is N₂O₄?

200

Tetrahydrocannabinol (THC) contains 80.15% carbon, 9.63% hydrogen, and 10.17% oxygen by mass. What is the empirical formula of THC?

What is C₂₁H₃₀O₂?

300

A molecular compound consists of 30.4% nitrogen and 69.6% oxygen. If the molecule contains 2 atoms of nitrogen, what is the molar mass of the molecule?

What is 92 g/mol?

400

A 4.08 g sample of a compound of nitrogen and oxygen contains 3.02 g of oxygen. What is the empirical formula?

What is N₂O₅?

500

What is the empirical formula for a compound that is comprised of 54.0% sodium, 8.50% boron, and 37.5% oxygen by mass?

What is Na₃BO_3?

Moles

100

What is the mass of 1.75 moles of Zn?

What is 114 g?

200

How many moles of hydrogen atoms are in six moles of Ca(OH)₂?

What is 12?

300

What is the molar mass of K3Fe(C2O4)3?

What is 437.15 g/mol?

400

Avogadro's number equals the number of:

a) atoms in one mol of O2

b) atoms in one mole of atoms

c) marbles in one mole of marbles

d) b and c

What is D (b and c)?

500

What is the mass percent of oxygen in K2CO3?

MM = 138.2 g/mol

What is 34.73%

Percent Composition

100

What is the percent composition of oxygen in CO₂?

What is 72.7%?

200

What is the mass percent of oxygen in K2CO3?

MM = 138.2 g/mol

What is 34.73%

300

What is the mass percent of oxygen in Fe₂(SO₄)₃?

What is 48.01%?

400

In the compound (NH₄)₂S₂O₃, which element is present in the largest percent by mass?

What is S?

500

A 10.000 g sample of water contains 11.19% H by mass. What would be the %H in a 20.000 g sample of water?

What is 11.19%

Periodic Table

100

Group or family 17 on the periodic table are known as what?

What are Halogens?

200

List the 7 diatomic elements.

What is H₂, N₂, F₂, O₂, I₂, Cl₂, and Br₂?

300

Name the following ionic compound: P₃N₅

What is phosphorus nitrate

400

A covalent bond is formed by what?

What is the sharing of electrons?

500

Which ion has twenty-six electrons?

a) Cr²⁺

b) Fe²⁺

c) Ni²⁺

d) Cu²⁺

What is Ni²⁺?