The area of a telescope lens is 6.668 × 103 mm2. What is the area in square feet (ft2)? Enter your answer in scientific notation

Explanation:

The area of a telescope lens is 6.668 × 10³ mm²

We need to convert the area in ft².

We know that,

It means,

or

So, the required answer is .

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol