Answer: 0.74 moles
Explanation:
The first step is to figure out the chemical formula for calcium phosphate. Since we know that calcium is a metal, this will be an ionic bond. Calcium is written as Ca and has a charge of +2. Phosphate is written as PO4 with a charge of -3. To come up with the subscripts for this formula, cross the charges. That means that you will get 
.
Next, calculate how many grams one molecule of calcium is. Calcium has an atomic weight of 40, and there are 3 molecules of calcium, so 40 x 3 = 120. Phosphorus has an atomic weight of 31, and there are 2 molecules of phosphorus, so 31 x 2 = 62. Oxygen has an atomic weight of 16, and there are 8 molecules of oxygen, so 16 x 8 = 128. Adding all of those together gives you 310 g.
Now, using stoichiometry, we can figure out the question. We know that there are 230 grams. We also know that one mole weighs 310 g. If you divide 230 by 310, you will get your answer, which is 0.74 moles.
Answer:
For this reason, the existence of Mesosaurus helps support the theory of continental drift; that is, the now-well-attested fact that South America and Africa were joined together into the giant continent Gondwana 300 million years ago before the continental plates supporting them broke apart and drifted.
Explanation:
Answer: option D. A molecular formula is sometimes a multiple of the empirical formula.
Explanation:
It’s C
Cooling a liquid til it freezes will cause a liquid to turn into a solid
Answer:
match emit 350 J light energy.
Explanation:
By law of conservation of energy, total energy before and after reaction for an isolated system remains constant.
Total energy for unlit match = 1000 j
When it burns type of energy released
thermal energy = 400 j
light energy --> it value is unknown which we have to find
also remaining match has 250 joule of chemical energy
applying law of conservation of energy
energy before match was unlit = energy after match was lit
1000 j = thermal energy + light energy + chemical energy of remaining match
1000 J = 400 J + light energy + 250 J
light energy = 1000 J - 400J - 250J
light energy = 350 J
Thus, match emit 350 J light energy.
