Answer:
a. 4.41 g of Urea
b. 1.5 g of Urea
Explanation:
To start the problem, we define the reaction:
2NH₃ (g) + CO₂ (g) → CH₄N₂O (s) + H₂O(l)
We only have mass of ammonia, so we assume the carbon dioxide is in excess and ammonia is the limiting reactant:
2.6 g . 1mol / 17g = 0.153 moles of ammonia
Ratio is 2:1. 2 moles of ammonia can produce 1 mol of urea
0.153 moles ammonia may produce, the half of moles
0153 /2 = 0.076 moles of urea
To state the theoretical yield we convert moles to mass:
0.076 mol . 58 g/mol = 4.41 g
That's the 100 % yield reaction
If the percent yield, was 34%:
4.41 g . 0.34 = 1.50 g of urea were produced.
Formula is (Yield produced / Theoretical yield) . 100 → Percent yield
Answer: Bubble algae are caused by lighting, nutrients and bubble algae spores. The spores were probably on the live rock. The lighting is a side effect of trying to keep photosynthetic corals.
Explanation:
To answer this question you need to know how to calculate the molecular weight of a molecule. The compound is having 1 Mg atom and 2 Cl atom, thus the molecular weight should be:
24.305+ 2*35.453= <span>95.211 gram/mol.
Then, the mass of 3 mol of MgCl would be:
3 mol * 95.211 gram/mol= 285.633 gram</span>
This question comes with this list of answer choices:
<span>A. CO₂
B.N₂O
C.NaCl
</span><span>
D.C₆H₁₂O₆
</span>
Answer: option C.NaCl
Justification.
1) When two diferent elements join together chemically they can form either a covalent bond or a ionic bond.
2) When the bonds are covalents the compound is called covalent, when the bonds are ionics the compound is called ionic.
3) To predict whether the compound is ionic or covalent, you must see the electronegativities of the elements.
4) Ionic compounds require the formation of ions, a posititve ion and a negative ion. The positive ion is formed when the element loses one or more electrons. The negative ion is formed when the element gains one or more electrons.
Then, in the formation of a ionic compound it is implicit the exchange of electrons (one element gains the electrons that the other lose) and this is possible, when the difference in electronegativities are high enough.
5) So, you must look at the electronegativities to make your prediction. In the given options, the compounds of the options A, B and D are between non-metals. Then, you can predict that their electronegativities are not as much differet as to form ions. They will form covalent bonds.
6) Being sodium and chloride a metal and non-metal, you can expect that their electronegativities differ quite enough to form the ionic bond (this is not true for any pair of non-metal and metal elements, but being them the only pair of metal - non metal elements, this is the only option).
This leads to the conclusion that the NaCl formula shows an ionic compound, and is the answer.
