According to the graph, how much potassium bromide can be dissolved in 100 g of warer at 40c?

77.8 g potassium bromide can be dissolved in 100 grams of water at 40°C.

Explanation:

In a given a line of KBr is straight. So ,from this we see that:

At 45 degree Celsius 80 grams of KBr is soluble in 100 grams of water.

At 90 degree Celsius 100 grams of KBr is soluble in 100 grams of water.

Slope from these point comes out to be : m

(45,80) , (90,100) :

According to question we want to determine the mass of KBr soluble in 100 grams of water at 40 degree Celsius. Let the mass of KBr at that temperature be y.

(40, y) , (45,80) :

Slope of the straight line as calculated above = m

y = 77.77777 ≈ 77.78 g

77.8 g potassium bromide can be dissolved in 100 grams of water at 40°C.

- decrease the number of plants and animals living in the water.

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"