Which of the following changes represent a physical change, rather than evidence

Question

Which of the following changes represent a physical change, rather than evidence of a chemical reaction? a. When a piece of zinc metal is placed in a solution of HCl, bubbles begin to form, and the zinc begins to dissolve. b. When a solution of Kl is mixed with a solution of Pb(NO_3)_2, a yellow solid is formed. c. When solid ammonium carbonate, (NH_2)_2CO_3. is heated, the solid disappears, and gaseous ammonia (NH_3), carbon dioxide (CO_2), and water (H_2O) are formed. d. When dry ice (solid CO_2) is allowed to stand at room temperature, a white cloud and gaseous CO, are formed. 2. Which of the following is not true regarding balanced chemical equations? a. The total mass of the reactants equals the total mass of the products. b. Chemical reactions represent chemical changes. c. The total number of atoms of each element is constant in both the reactants and products. d. The total number of compounds is constant in both the reactants and the products. 3. After balancing the following chemical reaction, what is the coefficient on H_2? N_2(g) + H_2(g) rightarrow NH_3(g) a. 1 b. 2 c. 3 d. 4 4. Solid aluminum metal reacts with oxygen gas to form aluminum oxide. When the equation is balanced, how many oxygen atoms are present on the reactants side? a. 3 b. 4 c. 6 d. 8 5. Which of the following is an incorrect definition of the type of reaction? a. Single-displacement reactions: A single compound reacts to form an individual element as the product. b. Decomposition reactions. A molecule Of compound reacts to form simpler compounds or individual elements. c. Combination reactions: 2 (or more) elements or compounds form a larger or more complex product. d. Double-displacement reactions: 2. compounds react to form 2 different compounds as products. 6. Which of the following reactions is most likely to take place?

Explanation / Answer

1.d

2.d

3.c

4.c

5.a

6.a

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.