Chemical Reactions

Balancing Equations

100

According to the law of conservation of matter, the amount of mass that goes into a chemical reaction must __________________________

What is . . .

come out? 

(allow other phrasing with same meaning)

200

In a chemical reaction, a total of 20 g of reactants are put in.  If one product has a mass of 12 g, what is the mass of the other product?

What is . . .

8 grams?

300

This would be how you would write 3 molecules of dihydrogen monoxide in formula form.

What is . . .

3 H₂O

400

____ Na + _____ F₂ --> ___NaF

What is . . .

2 Na + 1 F₂ --> 2 NaF

500

Write the balanced equation:

Aluminum combines with oxygen to make aluminum oxide.

What is . . .

4 Al + 3 O₂ --> 2 Al₂O₃

Predicting Products

100

In this type of chemical reaction, there is one reactant that breaks down to form multiple products.

What is . . . 

a decomposition reaction?

200

In the reaction Zn + HCl, the zinc will replace this element.

What is . ..

hydrogen (H)?

300

This is the type of reaction that occurs when you combine CuCl₂ + H₂S.

What is . . .

double replacement?

400

This is a prediction of the full balanced equation for:

C₆H₁₂ + O₂

What is . . .

C₆H₁₂ + 9 O₂ --> 6 CO₂ + 6 H₂O

500

This is the full balanced equation for 

Hydrogen sulfate + barium chloride

What is . . .

H₂SO₄ + BaCl₂ --> 2 HCl + BaSO₄

RedoxReactions

100

In an oxidation reaction, electrons are __________.

What is . . .

lost? 

(accept other answers with same meaning)

200

The oxidation state of an element before a reaction is -2.  The oxidation state of the same element after a reaction is zero.  Was this element oxidized or reduced?

This element was oxidized.

(Its oxidation state increased)

300

This is the oxidation state for each element in AgCl.

What is . . .

Ag = +1

Cl = -1

400

This is the oxidation state for each element in K₃PO₄

What is . . .

K= +1

P= +5

O= -2

500

In the reaction

2 Zn + O₂ --> 2 ZnO

this is the element that got reduced.

What is . . .

Oxygen (O)

(went from zero to -2 oxidation state)

Precipitation Reactions

100

If a substance is INsoluble, this is what would be written in (__) after its formula.

What is . . .

(s)

200

Fill in the ( ) of states that would be true for a precipitation reaction.

Reactant (__) + Reactant 2 (__) --> Product (__) + Product 2 (__)

What is . . . 

Reactant (aq) + Reactant 2 (aq) --> Product (s) + Product 2 (aq)

(One of the products should be s, all others aq)

300

Soluble or insoluble?

NaNO₃

What is . . .

soluble

400

This is the () that would be written after AgBr.

What is . . .

(s)

500

This is the proof of whether or not this is a precipitation reaction:

Co(NO₃)₂ (aq) + NaOH (aq)

What is . . . 

Co(NO₃)₂ (aq) + 2 NaOH (aq) --> 2 NaNO₃ (aq) + Co(OH)₂ (s)

The cobalt hydroxide product is insoluble which will form a precipitant.

Winter Trivia

100

This is the date of the winter solstice in the Northern hemisphere in 2025.

What is . . .

December 21?

200

This is the number of sides in a snowflake.

What is . . .

6?

300

This is the scientific name of the Northern lights.

What is . . .

Aurora Borealis?

400

This is the country that will host the 2026 Winter Olympics.

What is . . . 

Italy?

(In Milan and Cortina d'Ampezzo)

500

Within +/- 2,000, this is the number of LED lights that will be in the NYC Times Square ball on New Year's Eve this year.

What is . . . 

32,256 LED lights.