The answer to the first one is C. Strong attraction between ions
The answer to the second one is A. High melting points
Hope this helps :)
Joules? i m not sure about this E Q U A S I O N
Answer : The heat energy required to melt 2 kg of ice was, 667.7 kJ
Explanation :
First we have to calculate the moles of ice.
Now we have to calculate the heat energy.
As, heat energy required to melt 1 mole of ice = 6.01 kJ
So, heat energy required to melt 111.1 mole of ice = 111.1 × 6.01 kJ
= 667.7 kJ
Therefore, the heat energy required to melt 2 kg of ice was, 667.7 kJ
Answer:
17.65 grams of O2 are needed for a complete reaction.
Explanation:
You know the reaction:
4 NH₃ + 5 O₂ --------> 4 NO + 6 H₂O
First you must know the mass that reacts by stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction). For that you must first know the reacting mass of each compound. You know the values of the atomic mass of each element that form the compounds:
- N: 14 g/mol
- H: 1 g/mol
- O: 16 g/mol
So, the molar mass of the compounds in the reaction is:
- NH₃: 14 g/mol + 3*1 g/mol= 17 g/mol
- O₂: 2*16 g/mol= 32 g/mol
- NO: 14 g/mol + 16 g/mol= 30 g/mol
- H₂O: 2*1 g/mol + 16 g/mol= 18 g/mol
By stoichiometry, they react and occur in moles:
- NH₃: 4 moles
- O₂: 5 moles
- NO: 4 moles
- H₂O: 6 moles
Then in mass, by stoichiomatry they react and occur:
- NH₃: 4 moles*17 g/mol= 68 g
- O₂: 5 moles*32 g/mol= 160 g
- NO: 4 moles*30 g/mol= 120 g
- H₂O: 6 moles*18 g/mol= 108 g
Now to calculate the necessary mass of O₂ for a complete reaction, the rule of three is applied as follows: if by stoichiometry 68 g of NH₃ react with 160 g of O₂, 7.5 g of NH₃ with how many grams of O₂ will it react?

mass of O₂≅17.65 g
<u><em>17.65 grams of O2 are needed for a complete reaction.</em></u>
The element first discovered in the sun is the element Helium. This noble gas is the second most abundant element<span> in the universe and was </span>discovered<span> on the </span>sun<span> before it was discovered on the earth. Helium is the result of the nuclear fusion of hydrogen creating thus the mass of energy in the sun.</span>