Question

A chemical process dissolves 500 milligrams of iron oxide every 20 minutes. How long would it take this reaction to dissolve 2 lbs of iron oxide?

Answer 1

`\boxed{\text{25 da}}`

Step-by-step explanation:

Step 1. Convert pounds to milligrams

(a) Pounds to grams

`\text{Mass} = \text{2 lb} * \frac{\text{454 g}}{\text{1 lb}} = \text{910 g}`

(b) Grams to milligrams

`\text{Mass} = \text{910 g} * \frac{\text{1000 mg}}{\text{1 g}} = \text{910 000 mg}`

Step 2. Calculate the time

(a) Milligrams to minutes

`t = \text{910 000 mg}} * \frac{\text{20 min}}{\text{500 mg}} = \text{36 000 min}`

(b) Minutes to hours

`t = \text{36 000 min} * \frac{\text{1 h}}{\text{60 min}} = \text{610 h}`

(c) Hours to days

`t = \text{ 610 h} * \frac{\text{1 da}}{\text{24 h}} = \text{25 da}`

It will take
`\boxed{\textbf{25 da}}`to dissolve the iron oxide.

Answer 2

Answer : The time taken for the reaction is 36363.64 minutes.

Explanation :

First we have to convert the mass of iron oxide from milligram to pounds (lbs).

`1\text{ lbs}=453592mg`

or,

`1mg=(1)/(453592)\text{ lbs}`

As,
`1mg=(1)/(453592)\text{ lbs}`

So,
`500mg=(500mg)/(1mg)* (1)/(453592)\text{ lbs}=0.0011\text{ lbs}`

Now we have to calculate the time taken for the reaction.

As,
`0.0011\text{ lbs}` of iron oxide take time = 20 minutes

As,
`2\text{ lbs}` of iron oxide take time =
`\frac{2\text{ lbs}}{0.0011\text{ lbs}}* 20\text{ minutes}=36363.64\text{ minutes}`

Therefore, the time taken for the reaction is 36363.64 minutes.