Chemicals Reaction Online Practice
Which option is an example of a chemical change?
- baking a cake
A scientist is using a lithium ion battery to power her laptop. Which statement about the battery is correct?
-A new substance is formed as the battery is used.
Use the chemical reaction to answer the question.
2H2O2→2H2O +O2
Which statement about the reaction is correct?
-The H2O and O2 produced have the same mass as the original H2O2.
In the compound NH3, how are the atoms likely bonded to one another?
-Each hydrogen shares two electrons with nitrogen.
Which statement correctly explains how matter is conserved in chemical reactions?
-The number of atoms in the reactants is always equal to the number of atoms in the products.
In the formula
1N2 +3H2 → 2NH3 + 1H2
1 diatomic nitrogen (1N2) and 3 diatomic hydrogen (3H2) produce 2 ammonia (2NH3) with 1 diatomic hydrogen (1H2) left over. How can you change the formula so no diatomic hydrogen (H2) is left over?
-Remove a H2 molecule from the left side of the equation.
Suppose 20 atoms of hydrogen (H) react with chlorine (Cl) to produce 20 molecules of hydrochloric acid (HCl). According to the law of conservation of matter, how many atoms of chlorine reacted with the hydrogen?
-20
Which of the following describes what it means for a chemical equation to be balanced?
-It has the same number of atoms on both sides for each specific type of atom.
How many atoms are represented in the formula Na2HPO4?
-eight
Fluorine is in Group 17 of the periodic table. Two fluorine atoms bond to form highly reactive fluorine gas, F2. Which statement about the bond between the fluorine atoms is correct?
-The atoms share two valence electrons.
Use the generalized chemical equation to answer the question.
A + BC → AC + B
Which type of reaction does the generalized equation represent?
-single replacement
Use the equation to answer the question.
A + B → AB
Which type of reaction is modeled by the equation?
-synthesis
Which phrase defines reduction?
-a gain of one or more electrons
Which event occurs during an endothermic reaction?
-Heat and light are absorbed from the environment
Which statement about the reaction that forms water is correct?
-The reaction is exothermic because the total energy released by the products is greater than the energy absorbed in the reactants.
3 answers
- baking a cake
-A new substance is formed as the battery is used.
-The H2O and O2 produced have the same mass as the original H2O2.
-Each hydrogen shares two electrons with nitrogen.
-The number of atoms in the reactants is always equal to the number of atoms in the products.
-Remove a H2 molecule from the left side of the equation.
-20
-It has the same number of atoms on both sides for each specific type of atom.
-eight
-The atoms share two valence electrons.
-single replacement
-synthesis
-a gain of one or more electrons
-Heat and light are absorbed from the environment.
-The reaction is exothermic because the total energy released by the products is greater than the energy absorbed in the reactants.