imagine you have four food dyes to test A, B, C and D imagine that you are going to investigate which food dye diffuses more qui
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Answer : The concentration of Ca²⁺ ions is 2030 ppm CaCO₃ in the given solution.
Explanation :
Step 1 : Write chemical equation
The reaction of Ca ions and EDTA solution can be represented as follows.
Step 2 : Find moles of EDTA
The molarity of EDTA solution is 0.05 mo/L
The volume of EDTA required for the reaction is 10.14 mL
The volume in liters =
The moles of EDTA can be calculated using molarity formula which is given below.
We have 0.000507 moles of EDTA.
Step 3 : Find moles of Ca ions.
The mole ratio of Ca ions and EDTA is 1 : 1.
We have 0.000507 mol EDTA.
Moles of Ca²⁺ ions =
We have 0.000507 moles of Ca²⁺ ions.
Step 4 : Find mg of CaCO₃
The concentration of Ca²⁺ ions needs to be expressed as ppm CaCO₃.
We assume that all the Ca²⁺ ions come from CaCO₃.
So moles of CaCO₃ are same as moles of Ca²⁺ ions which is 0.000507.
Molar mass of CaCO₃ is 100.1 g/mol
Let us plug in the values in above formula.
We have 50.75 mg CaCO₃
Step 5 : Find ppm using the formula
ppm CaCO₃ is calculated using following formula.
The volume of CaCl₂ solution is 25 mL which is 0.025 L.
The concentration of Ca²⁺ ions is 2030 ppm CaCO₃ in the given solution.
Answer:
8.72 mol PbO₂
General Formulas and Concepts:
<u>Chemistry - Atomic Structure</u>
- Using Dimensional Analysis
- Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.
Explanation:
<u>Step 1: Define</u>
5.25 × 10²⁴ formula units PbO₂
<u>Step 2: Identify Conversions</u>
Avogadro's Number
<u>Step 3: Convert</u>
<u /> = 8.71803 mol PbO₂
<u>Step 4: Check</u>
<em>We are given 3 sig figs. Follow sig fig rules and round.</em>
8.71803 mol PbO₂ ≈ 8.72 mol PbO₂