How many mL of PURE water must be added to 60mL of 20% salt solution to make 12% salt solution?
(60 * .20) + (x * 0) = (60 + x) * .12
To determine how many mL of pure water must be added, we can set up an equation using the concept of the amount of salt in the solution. Here are the steps to solve the problem:
Step 1: Convert the percentage values to decimal form:
20% = 0.20
12% = 0.12
Step 2: Set up the equation:
Let "x" represent the amount of pure water to be added.
The total volume of the solution after adding pure water will be 60 mL + x mL.
The equation can be set up based on the amount of salt in the solution. Since the amount of salt remains constant before and after adding water, the equation becomes:
0.20 * 60 = 0.12 * (60 + x)
Step 3: Solve for "x":
12 = 0.12 * (60 + x) [Dividing both sides by 0.12]
12 / 0.12 = 60 + x
100 = 60 + x
Subtracting 60 from both sides gives:
100 - 60 = 60 + x - 60
40 = x
Therefore, 40 mL of pure water must be added to the 60 mL of 20% salt solution to obtain a 12% salt solution.
To solve this problem, you need to determine how much pure water should be added to a 60 mL solution of 20% salt solution to obtain a 12% salt solution. Here's the step-by-step process to find the solution:
1. Understand the problem: You are given a solution of 60 mL, containing 20% salt. You need to determine the volume of pure water to be added to obtain a 12% salt solution.
2. Set up the equation: Let x represent the volume of water to be added in milliliters (mL). The equation can be set up using the concept of the amount of salt in the initial solution equaling the amount of salt in the final solution.
Amount of salt in initial solution = Amount of salt in final solution
The amount of salt in the initial solution is the product of the volume of the solution (60 mL) and the concentration of salt (20%).
Amount of salt in initial solution = 60 mL * 0.20 = 12 mL
The amount of salt in the final solution is the product of the volume of the solution (60 mL + x mL) and the desired concentration of salt (12%).
Amount of salt in final solution = (60 mL + x mL) * 0.12 = 0.12x + 7.2 mL
Setting these two expressions equal to each other, we have:
12 mL = 0.12x + 7.2 mL
3. Solve the equation: Now, you need to solve the equation to find the value of x.
12 mL - 7.2 mL = 0.12x
4.8 mL = 0.12x
To isolate x, divide both sides of the equation by 0.12:
x = 4.8 mL / 0.12
x = 40 mL
4. Answer: Therefore, you need to add 40 mL of pure water to the 60 mL of 20% salt solution to obtain a 12% salt solution.