1.
CO2(g) + H2O(l) → H2CO3(aq)
Correct Answer
A. Synthesis
Explanation
The given chemical equation represents the reaction between carbon dioxide gas (CO2) and water (H2O) to form carbonic acid (H2CO3). This type of reaction, where two or more substances combine to form a single compound, is known as a synthesis reaction. In this case, carbon dioxide and water react to produce carbonic acid, making synthesis the correct answer.
2.
2 Na(s) + Cl2(g) → 2NaCl(s)
Correct Answer
A. Synthesis
Explanation
In the given chemical equation, two sodium atoms react with one chlorine molecule to form two sodium chloride molecules. This type of reaction, where two or more substances combine to form a more complex substance, is called synthesis.
3.
Cl2(g) + 2NaBr(aq) → 2NaCl(aq) + Br2(l)
Correct Answer
C. Single displacement
Explanation
The given chemical equation shows a single displacement reaction. In this reaction, chlorine gas (Cl2) reacts with sodium bromide (NaBr) to form sodium chloride (NaCl) and bromine (Br2). A single displacement reaction occurs when one element replaces another element in a compound. Here, chlorine (Cl2) replaces bromine (Br) in sodium bromide (NaBr) to form sodium chloride (NaCl) and bromine (Br2).
4.
2NaCl(l) → 2Na(s) + Cl2(g)
Correct Answer
B. Decomposition
Explanation
The given chemical equation represents the decomposition reaction. In this reaction, a compound (NaCl) breaks down into its constituent elements (Na and Cl2). This is evident from the fact that two moles of NaCl produce two moles of Na and one mole of Cl2. Therefore, the correct answer is decomposition.
5.
Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)
Correct Answer
C. Single displacement
Explanation
The given chemical equation shows a single displacement reaction. In this reaction, zinc (Zn) reacts with hydrochloric acid (HCl) to form zinc chloride (ZnCl2) and hydrogen gas (H2). The zinc atoms replace the hydrogen atoms in the hydrochloric acid, resulting in the formation of a new compound (zinc chloride) and the release of hydrogen gas. This type of reaction is characteristic of single displacement reactions, where one element replaces another element in a compound.
6.
2KClO3(s) → 2KCl(s) + 3O2(g)
Correct Answer
B. Decomposition
Explanation
The given chemical equation represents a decomposition reaction. In a decomposition reaction, a compound breaks down into simpler substances. In this case, 2KClO3(s) decomposes to form 2KCl(s) and 3O2(g). The reactant KClO3(s) is a compound composed of potassium (K), chlorine (Cl), and oxygen (O). It breaks down into the products KCl(s), which is potassium chloride, and O2(g), which is oxygen gas. Therefore, the correct answer is decomposition.
7.
CaCO3(s) → CaO(s) + CO2(g)
Correct Answer
B. Decomposition
Explanation
The given chemical equation represents a decomposition reaction. In this reaction, the compound CaCO3 is broken down into two separate substances, CaO and CO2. Decomposition reactions involve the breakdown of a single compound into two or more simpler substances. In this case, CaCO3 is decomposing into CaO and CO2.
8.
2Mg(s) + O2(g) → 2MgO(s)
Correct Answer
A. Synthesis
Explanation
The given chemical equation represents a synthesis reaction, which is a type of chemical reaction where two or more substances combine to form a new compound. In this case, magnesium (Mg) reacts with oxygen (O2) to form magnesium oxide (MgO). The reactants (2Mg and O2) combine to produce the product (2MgO), resulting in a new compound being formed. Therefore, the correct answer is synthesis.
9.
Ba(NO3)2(aq) + K2SO4(aq) --> BaSO4(s) + 2KNO3(aq)
Correct Answer
D. Double displacement
Explanation
In this reaction, Ba(NO3)2 and K2SO4 react to form BaSO4 and 2KNO3. Double displacement reactions occur when the cations and anions of two different compounds switch places to form new compounds. In this case, the Ba2+ cation from Ba(NO3)2 combines with the SO42- anion from K2SO4 to form BaSO4, while the 2K+ cations from K2SO4 combine with the NO3- anions from Ba(NO3)2 to form 2KNO3. Therefore, the reaction is a double displacement reaction.
10.
Fe(s) + CuSO4(aq) → FeSO4(aq) + Cu(s)
Correct Answer
C. Single displacement
Explanation
In this reaction, a single element (Fe) displaces another element (Cu) from its compound (CuSO4). This type of reaction is known as a single displacement reaction. The iron (Fe) atoms replace the copper (Cu) atoms in the compound, forming iron sulfate (FeSO4) and copper (Cu) as the products.
11.
C(s) + O2(g) → CO2(g)
Correct Answer
A. Synthesis
Explanation
The given chemical equation represents the synthesis reaction, where a single compound (C) combines with an element (O2) to form a new compound (CO2). In a synthesis reaction, two or more substances combine to form a more complex substance. In this case, carbon (C) combines with oxygen (O2) to form carbon dioxide (CO2).
12.
2P(s) + 3Cl2(g) → 2PCl3(g)
Correct Answer
A. Synthesis
Explanation
The given chemical equation represents a synthesis reaction, where two reactants (2P(s) and 3Cl2(g)) combine to form a single product (2PCl3(g)). In a synthesis reaction, two or more substances combine to form a more complex compound. In this case, phosphorus (P) and chlorine (Cl2) react to form phosphorus trichloride (PCl3).
13.
MgO(s) + H2O(l) → Mg(OH)2(s)
Correct Answer
A. Synthesis
Explanation
The given equation shows the reaction between MgO and H2O, resulting in the formation of Mg(OH)2. This is a synthesis reaction because two or more substances combine to form a single product. In this case, MgO and H2O combine to form Mg(OH)2.
14.
H2SO4 → H2O(l) + SO3(g)
Correct Answer
B. Decomposition
Explanation
The given reaction represents the decomposition of H2SO4 into H2O(l) and SO3(g). Decomposition reactions involve the breakdown of a compound into simpler substances. In this case, H2SO4 breaks down into water (H2O) and sulfur trioxide (SO3). Therefore, the correct answer is decomposition.
15.
Ca(OH)2(s) → CaO(s) + H2O(g)
Correct Answer
B. Decomposition
Explanation
The given chemical equation shows the decomposition of calcium hydroxide (Ca(OH)2) into calcium oxide (CaO) and water vapor (H2O). Decomposition is a type of chemical reaction where a compound breaks down into simpler substances. In this case, the compound Ca(OH)2 breaks down into CaO and H2O. Therefore, the correct answer is decomposition.
16.
3CuSO4 + 2 FeCl3 3CuCl2 + Fe2(SO4)3
Correct Answer
D. Double displacement
Explanation
The given equation represents a double displacement reaction. In this type of reaction, the cations and anions of two different compounds switch places to form two new compounds. In this case, CuSO4 and FeCl3 react to form CuCl2 and Fe2(SO4)3. The copper ions (Cu2+) from CuSO4 combine with the chloride ions (Cl-) from FeCl3 to form CuCl2, while the iron ions (Fe3+) from FeCl3 combine with the sulfate ions (SO4 2-) from CuSO4 to form Fe2(SO4)3. Therefore, the correct answer is double displacement.