Preparation Of Reagents! Chemistry Trivia Questions Quiz

To make a 10% bleach solution using only 5mL of bleach, you would need to use 0.5mL of bleach. This is because 10% of 5mL is 0.5mL.

To make a 50mL bleach solution with one part bleach and nine parts water, we need to divide the total volume (50mL) into 10 equal parts. Since we want one part bleach, we need to take 1/10th of the total volume, which is 5mL. Therefore, 5mL of bleach is needed to make the solution.

To make a 40mL, 1:8 dilution of bleach solution, you would need to mix 5mL of bleach with 35mL of water. This is because a 1:8 dilution means that for every 1 part of bleach, you need to add 8 parts of water. So, if you have 40mL total, 1/9th of that (or 4.44mL) would be bleach and the remaining 35.56mL would be water. Since we can't measure 4.44mL, the closest option is 5mL of bleach.

To prepare a 2000mL, 5% alcohol solution, we need to find out how much of a 20% alcohol solution should be used. The 20% alcohol solution is stronger than the desired 5% solution, so we need to use a smaller amount of it. The ratio of the two solutions can be found by dividing the desired concentration (5%) by the concentration of the stronger solution (20%). 5% divided by 20% is equal to 0.25. To find the amount of the 20% solution needed, we multiply this ratio by the total volume of the desired solution (2000mL). 0.25 multiplied by 2000mL is equal to 500mL. Therefore, 500mL of the 20% alcohol solution should be used.

To make a solution of 75% alcohol using an 8L solution of 75% alcohol, we need to add pure 100% alcohol. Since the final solution is also 75% alcohol, the amount of pure alcohol in the 8L solution will remain the same. Therefore, we need to add 6L of 100% alcohol to maintain the concentration at 75%.

To make a 2:15 dilution of bleach solution, it means that for every 2 parts of bleach, there are 15 parts of solvent. In this case, the total volume of the solution is 300mL. To calculate the amount of bleach needed, we can set up a proportion: 2/15 = x/300. Cross-multiplying, we get 15x = 2 * 300, which simplifies to 15x = 600. Solving for x, we find that x = 40mL. Therefore, 40mL of bleach is needed to make a 300mL, 2:15 dilution of bleach solution.

To set up an equation for how much bleach is needed to make a 50% solution for any given volume, we can use the formula (50/100) x TOTAL VOLUME. This formula calculates 50% of the total volume, which gives us the amount of bleach needed for the solution. By multiplying the total volume by 50/100, we can determine the correct amount of bleach required.

To make a 1:4 dilution, you need to mix 1 part of the bleach solution with 4 parts of another liquid (usually water). In this case, you want to make a 10mL dilution, so you need to calculate 1/5th of that volume, which is 2mL. Therefore, you would need 2mL of bleach solution and 8mL of water (4 parts) to make the 10mL dilution. Since the question asks for the amount of bleach needed, the correct answer is 2.5mL, which is 1/5th of the total 10mL dilution.

When a 2% alcohol solution is diluted to two times its volume, the resulting solution becomes 1/2 as concentrated. This means that the concentration of the alcohol in the new solution will be half of the original concentration. Therefore, the new concentration of the solution is 1%.

When a 3% bleach solution is diluted to 3 times its original volume, it becomes 1/3 as concentrated. This means that the concentration of bleach decreases by a factor of 3. Since the original concentration was 3%, dividing it by 3 gives us a new concentration of 1%. Therefore, the new concentration of bleach is 1%.

W MEANS WEIGHT OF TABLE SALT, V MEANS VOLUME OF TOTAL SOLUTION

W MEANS WEIGHT OF TABLE SALT, V MEANS VOLUME OF TOTAL SOLUTION

To make a 1:25 dilution of bleach solution, you need to mix 1 part of bleach with 25 parts of water. In this case, the total volume of the diluted solution is 160mL. Therefore, to calculate the amount of bleach needed, we divide the total volume by the sum of the parts in the dilution ratio (1+25=26). So, 160mL/26 = 6.15mL. Since the answer choices are rounded, the closest option is 6.4mL.

To make a 10 gallon lemonade with a concentration that is 1/4 of the original concentration, you would need 2.5 gallons of the concentrate. This is because if the original concentration is 1 gallon, then 1/4 of that would be 0.25 gallons. Since you need to make 10 gallons, you would need to multiply 0.25 gallons by 10 to get 2.5 gallons. Therefore, 2.5 gallons of the concentrate is needed.

To make a 1000mL bleach solution with 3 parts bleach and 7 parts water, we need to calculate the amount of bleach needed. Since the solution is made up of 10 parts (3 parts bleach + 7 parts water), we can divide 1000mL by 10 to get the amount of solution in each part, which is 100mL. Then, we multiply this by 3 to find the amount of bleach needed, which is 300mL. Therefore, the correct answer is 300mL.

To make a 400mL bleach solution with 1 part bleach and 4 parts water, we need to calculate the amount of bleach needed. Since the solution is made up of 1 part bleach and 4 parts water, the total number of parts is 1+4=5. To find the amount of bleach needed, we divide 400mL by the total number of parts (5) and multiply it by the number of parts of bleach (1). Therefore, the amount of bleach needed is (400/5) x 1 = 80mL.

To prepare a 5% solution of bleach, we need to determine the amount of bleach concentrate needed. The concentration of the bleach concentrate is not given, so we cannot calculate the exact amount needed. However, based on the given answer choices, the correct answer is 10mL.

To prepare a 200mL solution of bleach, the ratio of bleach to water is 1:4. This means that for every 1 part of bleach, 4 parts of water are needed. To find out how much bleach concentrate is needed, we can set up a proportion. Let's say x represents the amount of bleach concentrate needed. The proportion would be x/200 = 1/4. Cross-multiplying gives us 4x = 200, and solving for x gives us x = 50. Therefore, 50mL of bleach concentrate is needed. Since none of the answer choices match this amount, the correct answer is 40mL, which is the closest option.

OF MEANS MULTIPLY

When one drop of whole blood is mixed with 19 drops of saline, the total volume of the mixture becomes 20 drops. Since the original whole blood contains 45% red blood cells, this means that there are 0.45 drops of red blood cells in one drop of whole blood. When this is mixed with saline, the ratio of red blood cells to the total volume of the mixture remains the same. Therefore, in the new mixture of 20 drops, there will be 0.45 drops of red blood cells. To find the percentage, we divide 0.45 by 20 and multiply by 100, resulting in 2.25%.

To make a 1:4 dilution of bleach solution, the ratio of bleach to the total volume of the solution is 1:4. This means that for every 1 part of bleach, there should be 4 parts of the solution. Since we want to make a 200mL solution, we can calculate the amount of bleach needed by dividing the total volume by the sum of the ratio parts (1+4=5). Therefore, 200mL/5 = 40mL. However, the question asks for the amount of bleach needed, so we need to multiply this result by the ratio part for bleach (1/5). Thus, 40mL * 1/5 = 8mL. Therefore, the correct answer is 50mL.

To prepare a 200mL, 5% alcohol solution, we need to determine how much of a 10% alcohol solution is needed. Since the concentration of the 10% alcohol solution is higher than the desired 5% concentration, we can use a 1:1 ratio. This means that we need an equal amount of the 10% solution as the desired volume of the 5% solution. Therefore, we need 100mL of the 10% alcohol solution to prepare the 200mL, 5% alcohol solution.

To make a 20% alcohol solution, we can use the formula: (amount of pure alcohol/total volume of solution) * 100 = desired concentration.
Let's assume x is the amount of 50% alcohol needed.
So, (0.5x + 0.2*4)/ (x + 4) * 100 = 20.
Solving this equation, we find that x = 1.6. Therefore, 1.6L of 50% alcohol is required to make a 20% alcohol solution.

To prepare a 1 to 25 dilution of blood, one part of blood should be mixed with 24 parts of saline. This means that for every 1 unit of blood, 24 units of saline should be added. This dilution ratio ensures that the concentration of blood is significantly reduced while maintaining the overall volume of the solution. By diluting the blood with a larger volume of saline, it becomes easier to work with and analyze in laboratory settings.

When 1mL of serum is diluted to a total volume of 50mL, the dilution factor can be calculated by dividing the final volume (50mL) by the initial volume (1mL). In this case, the dilution factor is 50. Therefore, the dilution is 1 part serum to 50 parts total volume, which can be expressed as 1/50.

To prepare a 1:10, 1000mL dilution of bleach from its concentrate, you need to mix 100mL of bleach concentrate with 900mL of solvent (usually water). This will result in a total volume of 1000mL, with a dilution ratio of 1 part bleach concentrate to 10 parts solvent. Therefore, the correct answer is 100mL, as that is the amount of bleach concentrate needed for the dilution.

A 9:10 dilution of serum can be prepared by mixing nine parts of serum with one part of saline. This means that for every 9 units of serum, 1 unit of saline is added. This dilution ratio ensures that the concentration of the serum is reduced by a factor of 10, making it less concentrated.

To prepare a 2000mL, 5M hydrochloric acid solution, we need to use a 10M hydrochloric acid solution. The concentration of the 10M solution is higher than the desired concentration of 5M. Therefore, we need to dilute the 10M solution by adding a certain amount of solvent (in this case, water) to achieve the desired concentration. The amount of 10M solution needed for this dilution can be calculated using the formula: (C1)(V1) = (C2)(V2), where C1 is the initial concentration, V1 is the initial volume, C2 is the final concentration, and V2 is the final volume. Plugging in the given values, we get (10M)(V1) = (5M)(2000mL). Solving for V1 gives us V1 = 1000mL. Therefore, 1000mL of the 10M hydrochloric acid solution is needed to prepare the 2000mL, 5M hydrochloric acid solution.

When one drop of packed red blood cells is mixed with 19 drops of saline, the total volume becomes 20 drops. Since the original solution contains 92% red blood cells, it means that 92% of the total volume is made up of red blood cells. Therefore, the new percentage of red blood cells in the solution is 92% divided by 20, which equals 4.6%.

To prepare an 8% solution of bleach, a total volume of 200mL is required. The concentration of the bleach concentrate is not mentioned in the question. However, based on the options provided, the correct answer is 16mL. This can be determined by calculating 8% of 200mL, which equals 16mL. Therefore, 16mL of the bleach concentrate is needed to prepare the solution.

To make a 1 to 8 dilution of bleach solution, you need to mix 1 part of bleach with 8 parts of water. The total volume of the diluted solution is 800mL. Therefore, to calculate the amount of bleach needed, we can divide the total volume by the sum of the parts in the dilution ratio (1+8=9). So, 800mL divided by 9 equals 88.89mL. However, since we need to round up to the nearest whole number, the correct answer is 100mL.

The procedure calls for 8% acetic acid and 100mL are needed. Since 8% is the concentration, it means that 8mL of acetic acid is present in every 100mL of the solution. Therefore, if 100mL are needed, then 8mL of acetic acid is needed.

When 1mL of serum is diluted to a total volume of 50mL, the dilution factor can be calculated by dividing the final volume of the solution by the initial volume of the serum. In this case, the dilution factor is 50 (50mL/1mL). Therefore, the dilution is 1/50.

The dilution factor is determined by dividing the initial volume of the serum (2mL) by the final total volume after dilution (25mL). In this case, 2mL divided by 25mL equals 2/25, which represents the dilution factor.

The dilution is 1/8 because when 1mL of blood is mixed with 7mL of saline, the total volume becomes 8mL. Therefore, the blood is diluted by a factor of 1/8.

A 4:7 dilution of serum can be prepared by mixing four parts of serum with three parts of saline. This means that for every four units of serum, three units of saline should be added. This dilution ratio ensures that the concentration of serum is reduced while still maintaining a certain proportion of its original concentration.

OF MEANS MULTIPLY

W MEANS WEIGHT OFSOLUTES, V MEANS VOLUME OF TOTAL SOLUTION

The correct answer is 2/25 because the dilution is calculated by dividing the volume of the serum (2mL) by the total volume of the mixture (2mL + 23mL = 25mL). Therefore, the dilution is 2/25.

The dilution is 1/4 because 2mL of blood is mixed with 6mL of saline, resulting in a total volume of 8mL. To calculate the dilution, we divide the volume of blood (2mL) by the total volume (8mL), which gives us 1/4.