Respuesta :
[tex]\boxed{\text{4.79 g}}[/tex] of KBr is required to make 350 mL of 0.115 M KBr solution.
Further Explanation:
Concentration is defined as the amount or quantity of solute present in specific amount of solution. In order to evaluate concentration of various solutions, different concentration terms are used. Some of these are mentioned below.
1. Molarity (M)
2. Molality (m)
3. Mole fraction (X)
4. Parts per million (ppm)
5. Mass percent ((w/w) %)
6. Volume percent ((v/v) %)
Molarity is defined as the number of moles of solute that can be dissolved in one litre of the solution. It is denoted by M and its unit is mol/L.
The formula to calculate molarity of KBr solution is as follows:
[tex]\text{Molarity of KBr solution}=\dfrac{\text{Moles of KBr}}{\text{Volume (L) of KBr solution}}[/tex] ...... (1)
Rearrange equation (1) to calculate moles of KBr.
[tex]\begin{aligned}{\text{Moles of KBr}&=\left[{(\text{Molarity of KBr solution})\\&\text{ }\text{ }\text{ }(\text{Volume (L) of KBr solution})]\right]\end{aligned}}[/tex] ...... (2)
Substitute 0.115 M for molarity of KBr solution and 350 mL for volume of KBr solution in equation (2).
[tex]\begin{aligned}\text{Moles of KBr}&=(\text{0.115 M})(\text{350 mL)}\left(\dfrac{\text{10}^{-3}\text{ L}}{\text{1 mL}}\right)\\&=\text{0.04025 mol}\end{aligned}[/tex]
The formula to calculate moles of KBr is as follows:
[tex]\text{Moles of KBr}=\dfrac{\text{Mass of KBr}}{\text{Molar mass of KBr}}[/tex] ...... (3)
Rearrange equation (3) for mass of KBr.
[tex]\text{Mass of KBr}=(\text{Moles of KBr})(\text{Molar mass of KBr})[/tex] ...... (4)
Substitute 0.04025 mol for moles of KBr and 119.002 g/mol for molar mass of KBr in equation (4).
[tex]\begin{aligned}{\text{Mass of KBr}&=(\text{0.004025 mol})(\text{119.002 g/mol})\\&=\text{4.79 g}}\end{aligned}[/tex]
Therefore 4.79 g of KBr is required to make 350 mL of a 0.115 M KBr solution.
Learn more:
1. Determine the moles of water produced: https://brainly.com/question/1405182
2. What is the molarity of the stock solution? https://brainly.com/question/2814870
Answer details:
Grade: Senior School
Subject: Chemistry
Chapter: Concentration terms
Keywords: molarity, KBr, 350 mL, 0.115 M, 4.79 g, mass, molar mass, concentration terms, concentration, solute, moles of solute, volume.
