Question

1. match the name of the reaction to the equation.

$2nh_3 + h_2so_4 \
ightarrow (nh_4)2so_4$

1. match the name of the reaction to the equation.

$li_3n + 3nh_4no_3 \
ightarrow 3lino_3 + (nh_4)_3n$

1. choose the best answer.

a reaction in which heat is required is called ______.
\\(\circ\\) electrolysis
\\(\circ\\) dissociation
\\(\circ\\) thermal decomposition
\\(\circ\\) catalytic reaction

Explanation:

Question 7

Step1: Analyze the reaction type

The reaction is \( 2\text{NH}_3 + \text{H}_2\text{SO}_4
ightarrow (\text{NH}_4)_2\text{SO}_4 \). This is a combination of an acid (\(\text{H}_2\text{SO}_4\)) and a base (ammonia, which acts as a base in this context) to form a salt (\((\text{NH}_4)_2\text{SO}_4\)) and water? Wait, no, in this case, ammonia reacts with sulfuric acid to form ammonium sulfate. Actually, this is an acid - base reaction (neutralization) where ammonia (a base) reacts with sulfuric acid (an acid) to form a salt. Alternatively, it can be seen as a combination reaction (synthesis) as two substances combine to form one. But more accurately, it's an acid - base neutralization. However, if we consider the general type, it's a synthesis (combination) reaction? Wait, no, let's check the reactants and products. Reactants: \( \text{NH}_3 \) (a base) and \( \text{H}_2\text{SO}_4 \) (an acid). Products: \( (\text{NH}_4)_2\text{SO}_4 \) (a salt). So it's an acid - base neutralization reaction. But also, it can be classified as a synthesis reaction as two substances combine to form a single product. Wait, the reaction is \( 2\text{NH}_3+\text{H}_2\text{SO}_4 = (\text{NH}_4)_2\text{SO}_4 \). So two reactants form one product, so it's a synthesis (combination) reaction. Alternatively, acid - base neutralization. But in the context of matching reaction names, common reaction types are synthesis, decomposition, single replacement, double replacement, neutralization, etc. Let's re - evaluate. The reaction between ammonia (a base) and sulfuric acid (an acid) to form ammonium sulfate (a salt) is a neutralization reaction (acid + base → salt + water, but in this case, water is not formed as ammonia is a gas and reacts with the acid). But also, it can be seen as a synthesis reaction. However, the most appropriate name here is probably "synthesis" or "neutralization". But let's think again. The reaction is \( \text{NH}_3 \) (base) + \( \text{H}_2\text{SO}_4 \) (acid) → \( (\text{NH}_4)_2\text{SO}_4 \) (salt). So it's an acid - base neutralization reaction.

Step2: Identify the reaction name

The reaction \( 2\text{NH}_3+\text{H}_2\text{SO}_4
ightarrow(\text{NH}_4)_2\text{SO}_4 \) is an acid - base neutralization reaction (or a synthesis reaction as two substances combine to form one). But more precisely, it's a neutralization reaction (acid + base → salt).

Step1: Analyze the reaction type

The reaction is \( \text{Li}_3\text{N}+3\text{NH}_4\text{NO}_3
ightarrow3\text{LiNO}_3 + (\text{NH}_4)_3\text{N} \). Let's check the ions. In \( \text{Li}_3\text{N} \), we have \( \text{Li}^+ \) and \( \text{N}^{3 - } \). In \( \text{NH}_4\text{NO}_3 \), we have \( \text{NH}_4^+ \) and \( \text{NO}_3^- \). In the products, \( \text{LiNO}_3 \) has \( \text{Li}^+ \) and \( \text{NO}_3^- \), and \( (\text{NH}_4)_3\text{N} \) has \( \text{NH}_4^+ \) and \( \text{N}^{3 - } \). So the cations and anions have swapped partners. \( \text{Li}^+ \) from \( \text{Li}_3\text{N} \) combines with \( \text{NO}_3^- \) from \( \text{NH}_4\text{NO}_3 \), and \( \text{NH}_4^+ \) from \( \text{NH}_4\text{NO}_3 \) combines with \( \text{N}^{3 - } \) from \( \text{Li}_3\text{N} \). This is a double - replacement reaction, where the positive and negative ions of two ionic compounds exchange places.

Step2: Confirm the reaction type

A double - replacement reaction is of the form \( \text{AB}+\text{CD}
ightarrow\text{AD}+\text{CB} \). In our reaction, \( \text{Li}_3\text{N} \) (AB, A = \( \text{Li}^+ \), B=\( \text{N}^{3 - } \)) and \( \text{NH}_4\text{NO}_3 \) (CD, C = \( \text{NH}_4^+ \), D=\( \text{NO}_3^- \)) react to form \( \text{LiNO}_3 \) (AD, A=\( \text{Li}^+ \), D=\( \text{NO}_3^- \)) and \( (\text{NH}_4)_3\text{N} \) (CB, C=\( \text{NH}_4^+ \), B=\( \text{N}^{3 - } \)). So it's a double - replacement reaction.

Step1: Analyze each option

• Option 1: Electrolysis is the process of using electricity to break down a compound. It is not defined as a reaction that requires heat.
• Option 2: Dissociation is the separation of ions in a solution or the breaking of a compound into its constituent parts (usually in a solvent). It does not necessarily require heat.
• Option 3: Thermal decomposition is a reaction where a compound breaks down into simpler substances when heat is supplied. So a reaction in which heat is required (to decompose the compound) is called thermal decomposition.
• Option 4: A catalytic reaction is a reaction in which a catalyst is used to increase the rate of the reaction. A catalyst does not involve the requirement of heat (although some catalytic reactions may occur at elevated temperatures, the definition of a catalytic reaction is not based on the requirement of heat).

Step2: Choose the correct option

Based on the definitions, a reaction that requires heat is called thermal decomposition.

Answer:

The reaction is an acid - base neutralization (or synthesis) reaction. If we consider the common naming, it can be called a "synthesis (combination)" reaction or "neutralization" reaction. For the purpose of matching, the most appropriate name is likely "synthesis" or "neutralization". But if we look at the reactants and products, it's a synthesis (combination) reaction as two substances combine to form one product.

Question 8