1. Reactions follow the law of conservation of mass.
a.) True
b.) False
Answer: True
2. Reactants are the materials used in a chemical reaction.
a.) True
b.) False
Answer: True
3. In a chemical equation, the mass on the left of the arrow equals the mass on the right.
a.) True
b.) False
Answer: True
4. Diatomic molecules contain two atoms.
a.) True
b.) False
Answer: True
5. Coefficients are the numbers written before a symbol or formula.
a.) True
b.) False
Answer: True
6. (aq) stands for a solution involving any liquids.
a.) True
b.) False
Answer: False
7. A synthesis reaction involves the combination of two or more substances to form a compound.
a.) True
b.) False
Answer: True
8. In a single replacement reaction, sodium (Na) does not replace hydrogen.
a.) True
b.) False
Answer: False
9. Metals can replace nonmetals.
a.) True
b.) False
Answer: False
10. Combustion occurs when a substance combines with oxygen to produce light and heat.
a.) True
b.) False
Answer: True
Thank you in advance!
All of these look ok to me with my only misgivings about 9. Technically, if I react Na metal with HCl, I get MgCl2 + H2 which looks to me as if a metal is replace a non-metal. And I can think of a number of redox reactions in which the metal is oxidized and the non-metal is reduced (although those may NOT be replacement reactions).
zeros at the end of measurements may not be significants
1. To determine if reactions follow the law of conservation of mass, you need to understand that this law states that mass is neither created nor destroyed in a chemical reaction. To confirm if this is true, you should balance the chemical equation by making sure that the number of atoms of each element is the same on both sides of the equation. By balancing the equation, you can see that the mass of the reactants is equal to the mass of the products, thus following the law of conservation of mass. Therefore, the answer is True.
2. To determine if reactants are the materials used in a chemical reaction, you need to know that reactants are the starting substances that undergo a chemical change. When you identify the substances that are being transformed in a reaction, you can classify them as reactants. Therefore, the answer is True.
3. To determine if the mass on the left of the arrow equals the mass on the right in a chemical equation, you need to consider the law of conservation of mass. By balancing the equation, you can ensure that the number of atoms of each element is the same on both sides. Since the chemical equation is balanced, it implies that the mass on the left is equal to the mass on the right. Therefore, the answer is True.
4. To determine if diatomic molecules contain two atoms, you should know that diatomic molecules are molecules composed of two atoms of the same element. Examples include oxygen (O2), nitrogen (N2), and hydrogen (H2), among others. Since these molecules consist of two atoms, the answer is True.
5. To determine if coefficients are the numbers written before a symbol or formula, you need to understand that coefficients are used to balance chemical equations and represent the number of molecules or formula units involved in a reaction. They are written in front of the symbol or formula of the substance. Since this is accurate, the answer is True.
6. To determine if (aq) stands for a solution involving any liquids, you should know that (aq) stands for "aqueous," which indicates that a substance is dissolved in water. It does not include all liquids but specifically refers to water solutions. Therefore, the answer is False.
7. To determine if a synthesis reaction involves the combination of two or more substances to form a compound, you need to understand that a synthesis reaction occurs when two or more reactants combine to form a single product. This product is typically a compound. Therefore, the answer is True.
8. To determine if sodium (Na) does not replace hydrogen in a single replacement reaction, you should know that a single replacement reaction occurs when one element replaces another element in a compound. Sodium (Na) is a more reactive metal than hydrogen, so it can displace hydrogen from some compounds. Therefore, the answer is False.
9. To determine if metals can replace nonmetals, you need to understand that metals are generally more reactive than nonmetals. In a single replacement reaction, a metal can replace another metal in a compound but not nonmetals. Therefore, the answer is False.
10. To determine if combustion occurs when a substance combines with oxygen to produce light and heat, you need to know that combustion is a type of chemical reaction where a substance reacts with oxygen, usually from the air, to produce carbon dioxide and water vapor. This reaction often produces light and heat as byproducts. Therefore, the answer is True.