CHEM 105 Exam 1 Review

sig figs

100

The number of significant figures in this number. 

0.0090

What is 2 sig figs?

200

The number of significant figures in this number.

198000

What is 3 sig figs?

300

The significant figures that the answer is supposed to have.

18.98 - 0.9

What is 3 sig figs?

400

The number of significant figures that the quotient is supposed to have.

15.99 divided by 3.40000

What is 6 sig figs?

500

The number of significant figures that the product is supposed to have.

0.3762 x 0.30

What is 2 sig figs?

mols to molecules

100

The number of molecules in a mole.

What is 6.022 x 10^23 molecules?

200

The number of moles of zinc that are in 8.52×10¹⁶ molecules of zinc.

What is 1.42 × 10^-7 mol zinc?

300

The mass of 2.75 moles of H₂O.

What is 49.6 g?

400

The number of moles of carbon atoms are in 2.4×10^22 molecules of C₆H₁₂O₆

What is 0.239mol C?

500

The mass of oxygen in 2.5×10^21 molecules of H₂SO₄

What is 0.266g of oxygen?

jimmy neutron

100

The number of protons in carbon-14.

What is 6?

200

The number of neutrons in uranium-238.

What is 146 neutrons?

300

A neutral carbon-14 atom has 6 protons and 8 neutrons.The number of electrons that is has. 

What is 6 electrons?

400

A sodium ion, Na⁺, has 11 protons and 12 neutrons. The number of electrons that it has.

What is 10 electrons?

500

A magnesium ion, Mg²⁺, has 12 protons and 12 neutrons. The number of electrons that is has.

What is 10 electrons?

rxns

100

This type of reaction occurs when two or more substances combine to form a single product.

What is a synthesis reaction?

200

When aqueous solutions of barium chloride and sodium sulfate are mixed, a precipitate of barium sulfate forms. Write the balanced chemical equation.

BaCl_2(aq)+Na₂SO_4(aq)→BaSO_4(s)+2NaCl_(aq)

300

Magnesium metal reacts with nitrogen gas to form magnesium nitride. Write the balanced equation.

3Mg_(s)+N_2(g)→Mg₃N_2(s)

400

Propane (C₃H₈) burns in oxygen to form carbon dioxide and water. Write the balanced equation.

C₃H_8(g)+5O_2(g)→3CO_2(g)+4H₂O_(l)

500

This reaction occurs when aluminum metal reacts with oxygen gas to form aluminum oxide. Write the balanced chemical equation.

4Al_(s)+3O_2(g)→2Al₂O_3(s)

the secret formula

100

The formula for the phosphate polyatomic ion. 

What is PO₄^3-?

200

The chemical formula for Iron (III) sulfide.

Fe₂S₃

300

This compound is potassium nitrate. What is its chemical formula?

KNO₃

400

his compound is copper(II) sulfate. What is its chemical formula?

CuSO₄

500

This compound is magnesium hydroxide. What is its chemical formula?

Mg(OH)₂