The correct answer is 3.Silver
Answer: D. It is a base because it increases the concentration of hydroxide ions.
Explanation: A base is a substance which dissociates to give hydroxide ions in water.
An acid is a substance which dissociates to give hydrogen ions in water.
![NaOH\rightarrow Na^++OH^-](https://tex.z-dn.net/?f=NaOH%5Crightarrow%20Na%5E%2B%2BOH%5E-)
So
is a base as it gives
ions when dissolved in water.
Answer: Out of the given options bonds connecting atoms in reactants break, and bonds connecting atoms in products form are the changes which takes place when a chemical change occurs.
Explanation:
A change that leads to the change in chemical composition of a substance is called a chemical change.
For example, ![2NH_{3} \rightarrow N_{2} + 3H_{2}](https://tex.z-dn.net/?f=2NH_%7B3%7D%20%5Crightarrow%20N_%7B2%7D%20%2B%203H_%7B2%7D)
Here, bond between the reactant atoms nitrogen and hydrogen is broken down.
On the other hand, bond connecting the products that is
and
is formed.
Thus,, we can conclude that out of the given options bonds connecting atoms in reactants break, and bonds connecting atoms in products form are the changes which takes place when a chemical change occurs.
Answer
The element that is oxidized is Si and the one that is reduced is F₂.
Explanation
Si + 2F₂ → SiF₄
The given reaction is an oxidation-reduction (redox) reaction:
Oxidation: Si → Si⁴⁺ + 4e⁻
Reduction: 2F₂ + 4e⁻ → 4F⁻
Si is a reducing agent, and F₂ is an oxidizing agent.
An oxidizing agent gains electrons and is reduced in a chemical reaction.
A reducing agent loses electrons and is oxidized in a chemical reaction.
Therefore, the element that is oxidized is Si and the one that is reduced is F₂.
Answer: The mole fraction of chloroform in this solution is 0.41
Explanation:
To calculate the moles, we use the equation:
a) moles of
b) moles of
To calculate the mole fraction, we use the formula:
![\text{Mole fraction of a component}=\frac{\text{Moles of the component}}{\text{total moles}}](https://tex.z-dn.net/?f=%5Ctext%7BMole%20fraction%20of%20a%20component%7D%3D%5Cfrac%7B%5Ctext%7BMoles%20of%20the%20component%7D%7D%7B%5Ctext%7Btotal%20moles%7D%7D)
![\text{Mole fraction of chloroform}=\frac{\text{Moles of chloroform}}{\text{total moles}}=\frac{0.41}{0.41+0.59}=0.41](https://tex.z-dn.net/?f=%5Ctext%7BMole%20fraction%20of%20chloroform%7D%3D%5Cfrac%7B%5Ctext%7BMoles%20of%20chloroform%7D%7D%7B%5Ctext%7Btotal%20moles%7D%7D%3D%5Cfrac%7B0.41%7D%7B0.41%2B0.59%7D%3D0.41)
The mole fraction of chloroform in this solution is 0.41