Chem. and Phys. Properties and Changes and Chem. Equations

Chemical Reactions
1.Look at the chemical equation above. The subscript 4 in the reactants indicates that   

• A.there are four products that will be formed. 
• B.there are four elements present in the reactants.
• C.there are four moles of phosphorus present in the reactants.
• D.there are four atoms of phosphorus present in the reactants.

A substance is found to be reactive, flammable, soluble, and explosive. Which of these observations is a physical property? 

• A.flammable
•  B.explosive 
• C.reactive 
• D.soluble

In a chemical reaction, the total mass of the reactants is 10.0 grams. After the reaction, the total mass of the products must be: 

• A.exactly 10.0 grams. 
• B.less than 10.0 grams. 
• C.more than 10.0 grams. 
• D.exactly 20.0 grams.

The substances in a chemical reaction that are combined or separated to form new substances are the _______. 

• A.coefficients 
• B.chemical equations 
• C.products 
• D.reactants

Adam is trying to identify a solid. He places a small amount of the substance in an acid solution and observes whether or not a reaction takes place. This test is based on a _______ property. 

• A.physical 
• B.radical 
• C.biological 
• D.chemical

Gerald's science teacher mixed room temperature samples of hydrochloric acid and sodium hydroxide in a large beaker. The solution still looked clear like water, but when the students carefully touched the beaker one at a time, it felt warm to the touch. 
Why did the beaker most likely feel warm? 

• A.The two liquids were not soluble in water. 
• B.The release of a gas heated the solution. 
• C.The energy of mixing warmed the solution. 
• D.A chemical reaction was producing a new substance.

In a chemical reaction, the products are 

• A.all of the chemical formulas that are used during the reaction. 
• B.the number of atoms of each chemical present in the reaction. 
• C.the new substances that are formed during the reaction. 
• D.the substances that are broken apart or combined in the reaction.

Water is a very unique substance because it can exist in all three phases of matter (solid, liquid, gas) within the normal temperature ranges found on Earth.
When one observes the phase of matter of water, one observes a   property of matter.

•  A.geological 
• B.chemical 
• C.physical 
• D.biological

10. Which of the following statements describes a physical property? .

• A.The substance produces an acid when dissolved in water.
• B.The substance has a higher density than water.
• C.The substance forms a solid when reacted with silver nitrate.
   
• D.The substance is highly reactive

Propane burns in oxygen to produce carbon dioxide and steam.
Which of the chemical equations matches the reaction above? 

• A.C₃H₈ + 4O₂ 2CO₂ + 4H₂O 
• B.C₃H₈ + 5O₂ 3CO₂ + 4H₂O
• C.  C₃H₈ + 6O₂ 2CO₂ + 8H₂O 
• D.C₃H₈ + 6O₂ 3CO₂ + 6H₂O