Which substance is a base?
HCOOH
RbOH
[tex]$H _2 CO _3$[/tex]
[tex]$NaNO _3$[/tex]
Answer (2)
Acids donate protons or accept electrons.
Bases accept protons or donate electrons, often containing hydroxide ions (OH-).
Salts are formed from acid-base reactions.
RbOH is the only base among the given substances because it contains O H − .
The answer is R b O H .
Explanation
Understanding the Problem We are given four chemical formulas: HCOOH, RbOH, H 2 C O 3 , and N a N O 3 . Our task is to identify which of these substances is a base. To do this, we need to understand the basic definitions of acids, bases, and salts.
Definitions of Acids, Bases, and Salts Acids are substances that donate protons (H+) or accept electrons. Common examples include hydrochloric acid (HCl) and sulfuric acid ( H 2 S O 4 ). Bases, on the other hand, accept protons or donate electrons, and they often contain hydroxide ions (OH-) or produce them when dissolved in water. Salts are compounds formed from the reaction between an acid and a base.
Analyzing Each Substance Now, let's examine each substance individually:
HCOOH (Formic acid): This is a carboxylic acid, meaning it donates protons and is therefore an acid.
RbOH (Rubidium hydroxide): This compound contains a metal (Rb) and a hydroxide ion (OH-). When dissolved in water, it dissociates to release hydroxide ions, making it a strong base.
H 2 C O 3 (Carbonic acid): This is formed when carbon dioxide dissolves in water. It's a weak acid, meaning it donates protons but not as readily as strong acids.
N a N O 3 (Sodium nitrate): This is a salt formed from the reaction of nitric acid ( H N O 3 ) and sodium hydroxide (NaOH). It's neither an acid nor a base.
Conclusion Based on our analysis, RbOH (rubidium hydroxide) is the only substance that fits the definition of a base because it contains hydroxide ions and releases them in solution.
Examples
Understanding acids and bases is crucial in many real-world applications. For example, in agriculture, farmers need to monitor the pH of the soil to ensure optimal plant growth. If the soil is too acidic, they might add a base like lime (calcium carbonate) to neutralize the acidity. Similarly, in medicine, antacids are used to neutralize excess stomach acid, providing relief from heartburn. In chemistry, understanding acid-base reactions is fundamental for many industrial processes, such as the production of fertilizers, pharmaceuticals, and plastics. Knowing how to identify acids and bases allows us to control and optimize these processes for various applications.
The only substance that is a base among the given options is RbOH (Rubidium hydroxide) because it contains hydroxide ions. The other substances either classify as acids or salts. Thus, the chosen answer is oxed{RbOH} .
;
