Question
Consider a reaction with a half-life of 20 minutes. If the amount of material remaining after 2 hours is 5 0 g 50 g, how much material was present at the start? ans in grams
Answers
GPT 3.5
To calculate the amount of material present at the start, we need to determine how many half-lives occurred during the 2-hour time period.
1 half-life = 20 minutes or 20/60 = 1/3 hours
2 hours = 2 x 60 minutes = 120 minutes = 4 half-lives
If the amount remaining after 4 half-lives is 50 grams, the initial amount present can be calculated using the formula:
Amount = Initial Amount x (1/2)^(number of half-lives)
50 = Initial Amount x (1/2)^4
50 = Initial Amount x (1/16)
Initial Amount = 50 x 16 = 800 grams
Therefore, the amount of material present at the start was 800 grams.
1 half-life = 20 minutes or 20/60 = 1/3 hours
2 hours = 2 x 60 minutes = 120 minutes = 4 half-lives
If the amount remaining after 4 half-lives is 50 grams, the initial amount present can be calculated using the formula:
Amount = Initial Amount x (1/2)^(number of half-lives)
50 = Initial Amount x (1/2)^4
50 = Initial Amount x (1/16)
Initial Amount = 50 x 16 = 800 grams
Therefore, the amount of material present at the start was 800 grams.