When you cook food like eggs, this is a chemical change. Agree.
The runny egg turns into a solid. One type of matter must be changing into another type
When you cook food like potatoes, this is a chemical change. Agree.
Boiling potatoes causes changes in the structure of the starch. Higher heat as in baking, roasting, or frying causes the development of a harder crust on the potato. This suggests that chemical changes have taken place.
When a candle burns, the wick of the candle and wax turn into nothing. Disagree.
The <em>Law of Conservation of Mass</em> says that <em>you can’t turn matter into nothing</em>. What must be happening is that the wick and the wax are changing into other substances that we can’t see, such as colourless gases of carbon dioxide and water vapour.
Answer: 116 calories of energy
Explanation:
A calorie is a non-standard unit of energy.
On combustion,
1 gram Carbohydrates = 4 calories,
1 gram protein = 4 calories,
1gram fat = 9 calories.
Therefore,
15 grams of carbohydrates = (15*4) = 60
5 grams of protein = (5*4) = 20
4 grams of fats = (4*9) = 36
Then add up: 60 + 20 + 36 = 116 calories of energy
<u>Answer:</u> The correct answer is Option b.
<u>Explanation:</u>
The balanced equilibrium reaction for the ionization of calcium fluoride follows:
s 2s
The expression for solubility constant for this reaction will be:
![K_{sp}=[Ca^{2+}][F^-]^2](https://tex.z-dn.net/?f=K_%7Bsp%7D%3D%5BCa%5E%7B2%2B%7D%5D%5BF%5E-%5D%5E2)
We are given:
Putting values in above equation, we get:
To calculate the solubility in g/L, we will multiply the calculated solubility with the molar mass of calcium fluoride:
Molar mass of calcium fluoride = 78 g/mol
Multiplying the solubility product, we get:
Hence, the correct answer is Option b.
