Answer:
Hydrogen is an element
Explanation:
Hydrogen is an element with only hydrogen atoms, whereas air, carbon dioxide, and water are all made up of multiple elements with different types of atoms.
Answer: Option (d) is the correct answer.
Explanation:
Since the given formula is 
. According to cross method formula, magnesium has +2 charge so, 
is multiplied by 2.
Thus, 1 molecule of magnesium phosphate will contain 2 atoms of phosphorus.
Therefore, three molecules of magnesium phosphate contains following number of atoms.
Hence, we can conclude that there are 6 atoms of phosphorus in three molecules of magnesium phosphate, .
Hello there,
The answer to your question is:
C. Zinc
Hope this answer helps you.
Answer:
CH₂ ; 67.1 %
Explanation:
To determine the empirical formula we need to find what the mole ratio is in whole numbers of the atoms in the compound. To do that we will first need the atomic weights of C and H and then perform our calculation
Assume 100 grams of the compound.
# mol C = 85.7 g / 12.01 g/mol = 7.14 mol
# mol H = 14.3 g / 1.008 g/mol = 14.19 mol
The proportion is 14.9 mol H/ 7.14 mol C = 2 mol H/ 1 mol C
So the empirical formula is CH₂
For the second part we will need to first calculate the theoretical yield for the 12.03 g NaBH₄ reacted and then calculate the percent yield given the 0.295 g B₂H₆ produced.
We need to calculate the moles of NaBH₄ ( M.W = 37.83 g/mol )
1.203 g NaBH₄ / 37.83 g/mol = 0.0318 mol
Theoretical yield from balanced chemical equation:
0.0318 mol NaBH₄ x 1 mol B₂H₆ / mol NaBH₄ = 0.0159 mol B₂H₆
Theoretical mass yield B₂H₆ = 0.0159 mol x 27.66 g/ mol = 0.440 g
% yield = 0.295 g/ 0.440 g x 100 = 67.1 %
Answer:
1. 0.00040 calories
2. 8.57 calories
3. 0.196 calories
4. 68 calories
5. 243 calories
6. 83680 joules
7. 1,054,368 joules
8. 2.45 calories
9. 556 (it says calories to calories so it wouldn't change)
10. 28367.52 joules
11. 59.6 calories
12. 449.6 joules
13. 0.00234 calories
14. 23292.328 joules
15. 22877693.6 joules
Hope this helps!
Explanation:
