Chemical Reactions - Assessment

1.

Multiple Select

45 sec

1 pt

Harrison is making cake. He prepares some batter and places it into the oven. Harrison realizes a gas, carbon dioxide, is coming out of the batter as it bakes.

Harrison está haciendo pastel. Prepara un batido y lo mete en el horno. Harrison se da cuenta de que sale gas, dióxido de carbono, de la masa mientras se hornea.

Which options are true about carbon dioxide?

¿Qué opciones son ciertas sobre el dióxido de carbono?

It is a new gas that forms during baking.

It is made of atoms that did not exist before.

It is the dough changing states from solid to gas.

It is formed from the atoms of the batter

2.

Multiple Choice

30 sec

1 pt

The element sodium (Na) is a soft solid that will react explosively with water. The element chlorine (Cl) is a toxic gas. When these two elements combine, they produce a stable, crystalline solid known commonly as table salt (NaCl).

How would you explain this?

El elemento sodio (Na) es un sólido blando que reacciona explosivamente con el agua. El elemento cloro (Cl) es un gas tóxico. Cuando estos dos elementos se combinan, producen un sólido cristalino estable conocido comúnmente como sal de mesa (NaCl). ¿Cómo explicarías esto?

When substances combine to form new substances, the properties of the reactants are preserved.

The properties of each of the two original elements are combined to give salt its properties.

Sodium and chlorine become different elements during the reaction.

When substances combine to form new substances, the properties of the resulting substances will be different.

3.

Multiple Choice

30 sec

1 pt

Consider burning a hot cheeto. This is a chemical reaction. The hot cheeto, flame, and oxygen in the air enter a chemical reaction and produce ash and some other things.

Considere quemar un cheeto caliente. Ésta es una reacción química. El cheeto caliente, la llama y el oxígeno del aire entran en una reacción química y producen cenizas y algunas otras cosas.

Which statement would be true?

Ash is a different substance than the hot cheeto.

The atoms of wood and oxygen disappear during the burning.

Ash has similar properties to oxygen.

The atoms of the ash did not exist before.

4.

Multiple Choice

30 sec

1 pt

Complete the sentence.

During a chemical reaction, atoms ________.

Completa la oración. Durante una reacción química, los átomos ________.

can appear

can disappear

get rearranged

stop moving and vibrating

5.

Multiple Choice

30 sec

1 pt

What always happens in a chemical reaction?

¿Qué sucede siempre en una reacción química?

Some atoms of existing substances disappear.

Some substances change phase.

New atoms appear and form new substances.

New substances form from atoms of existing substances.

6.

Multiple Choice

30 sec

1 pt

Identify the product(s) in the following chemical reaction:

Chromium oxide + Carbon → Chromium + Carbon monoxide

Chromium and carbon.

Chromium and carbon monoxide.

Chromium and carbon dioxide.

Chromium oxide and carbon.

7.

Multiple Choice

30 sec

1 pt

How many iron (Ag) atoms are reactants in this equation?

4Ag + 3O2 → 2Ag2O

4

2

3

0

8.

Multiple Choice

30 sec

1 pt

Why are numbers placed before the elements and molecules in a chemical equation?

¿Por qué se colocan los números antes de los elementos y las moléculas en una ecuación química?

To represent if an element or molecule is a liquid, gas, or solid.

To balance the equation so that it has the same number of atoms of each element on each side.

To make sure there's always more reactants than products.

To show whether a substance is an element or molecule.

9.

Multiple Choice

30 sec

1 pt

In chemical reactions, a product is _________.

En reacciones químicas, un producto es _________.

any substance that is made of the greatest number of atoms

any substance that is made from the least number of atoms

any substance that is to the left of the arrow

any substance to the right of the arrow

10.

Multiple Choice

30 sec

1 pt

What is the role of the arrow sign in a chemical reaction?

¿Cuál es el papel del signo de flecha en una reacción química?

Making sure atom counts on each side are the same.

Separating products and reactants.

Showing which substances were in the container first and which substances were added later.

Showing which substances are solids and which are liquids or gases.

11.

Multiple Choice

30 sec

1 pt

A substance with two gold atoms is combined with a substance with one gold atom to form one product. What is true of the product?

There will be six gold atoms in the product.

There will be no gold in the product.

Some of the gold will evaporate into the air.

There will be three gold atoms in the product.

12.

Multiple Choice

30 sec

1 pt

In a chemical reaction, the mass of the reactants is 200 grams. Which of the following could represent the mass of the products?

26.6 grams.

200 grams

3.3 grams.

2000 grams.

13.

Multiple Choice

30 sec

1 pt

In a chemical reaction, the mass of the reactants is 65.3 grams. The reaction produces two products, and the mass of Product 1 is 25.3 grams. What is the mass of the second product?

40 grams.

7.2 grams.

35 grams.

42 grams.

14.

Multiple Choice

30 sec

1 pt

Which of the following describes the law of conservation of mass?

¿Cuál de los siguientes describe la ley de conservación de la masa?

The mass of the reactants is greater than the mass of the products.

The mass of the products equals the mass of the reactants.

The mass of the products is greater than the mass of the reactants.

The products will have the same states of matter as the reactants.

15.

Multiple Choice

30 sec

1 pt

Complete the sentence.

During a chemical reaction, __________.

a small amount of matter is destroyed during the process

the mass of the atoms of the product(s) is greater than that of the reactant(s)

a new substance(s) with the same number of atoms as the initial substance(s) is formed

the number of atoms in the product(s) is less than that of the reactant(s)

16.

Multiple Choice

30 sec

1 pt

Which of the following indicates that a chemical reaction absorbs energy?

¿Cuál de los siguientes indica que una reacción química absorbe energía?

New substances are formed.

Sound is heard.

Mass is increased.

The container feels colder.

17.

Multiple Choice

30 sec

1 pt

Which of the following indicates that a chemical reaction releases energy?

¿Cuál de los siguientes indica que una reacción química libera energía?

The reactant changes color.

Mass is reduced.

Light is produced.

Substances are changed.

18.

Multiple Choice

30 sec

1 pt

"Meals, Ready to Eat" are an instant hot meal developed by the U.S. military for troops. The meal heats up when water is added to the magnesium metal tray because the chemical reaction between water and magnesium is an _________.

energy-conserving reaction

exothermic reaction

evaporation reaction

endothermic reaction

19.

Multiple Choice

30 sec

1 pt

When you strike a match, this is an example of a ____________ because heat and light are produced.

endothermic reaction

exothermic reaction

the temperature decreased

energy was absorbed during this reaction.

20.

Multiple Choice

30 sec

1 pt

Mixing baking soda and vinegar is an example of an endothermic reaction. This means...

energy is taken in during the chemical reaction.

baking soda and vinegar are products in this reaction.

energy is released during the chemical reaction.

there is no change in energy during the chemical reaction.

21.

Multiple Choice

30 sec

1 pt

Which statement about energy and chemical reactions is true?

¿Qué afirmación sobre la energía y las reacciones químicas es verdadera?

Chemical reactions do not involve changes in energy.

All chemical reactions absorb energy.

Some chemical reactions absorb energy, and some release energy.

All chemical reactions release energy.

22.

Multiple Choice

30 sec

1 pt

The graph shows the energy change that occurs during a chemical reaction. What conclusion can be reached based upon the graph?

El gráfico muestra el cambio de energía que ocurre durante una reacción química. ¿A qué conclusión se puede llegar con base en el gráfico?

Energy was neither absorbed nor released during this reaction.

The energy of the reactants is less than the energy of the products.

The energy of the products is less than the energy of the reactants.

The energy of the products and the energy of the reactants are equal.

23.

Multiple Select

45 sec

1 pt

Study the graph. Which options are correct about this graph?

Estudia el gráfico. ¿Qué opciones son correctas sobre este gráfico?

The reaction is exothermic.

The reaction absorbs energy.

The reactants have more energy than the products.

The products have more energy than the reactants.

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