Answer:
D
Explanation:
As you move down anything, towards the earth, (gravitational) potential energy decreases. This eliminates options B and C.
By the law of conservation of energy, the energy of the system stays the same. However the energy may be converted into different forms. In this case, the potential energy is converted into kinetic energy - this is what makes people move faster as they go down the slope. This makes option A wrong and option D right.
The answer is d because it said so
Answer:
2.61 g of NO will be formed
The limiting reagent is the O₂
Explanation:
The reaction is:
4NH₃ + 5O₂ → 4NO + 6H₂O
We convert the mass of the reactants to moles:
3.25g / 17 g/mol = 0.191 moles of NH₃
3.50g / 32 g/mol =0.109 moles of O₂
Let's determine the limiting reactant by stoichiometry:
4 moles of ammonia react with 5 moles of oxygen
Then, 0.191 moles of ammonia will react with (0.191 . 5) / 4 = 0.238 moles of oxygen. We only have 0.109 moles of O₂ and we need 0.238, so as the oxygen is not enough, this is the limiting reagent
Ratio with NO is 5:4
5 moles of oxygen produce 4 moles of NO
0.109 moles will produce (0.109 . 4)/ 5 = 0.0872 moles of NO
We convert the moles to mass, to get the answer
0.0872 mol . 30g / 1 mol = 2.61 g
Answer: 19.8 l
Explanation:
1) Chemical equation:
2Ca + O₂ → 2CaO
2) Mole ratios: 2 mol Ca : 1 mol O₂ : 2 mol CaO
3) Convert 35.4 g of Ca to moles:
n = mass in grams / molar mass = 35.4 g / 40.1 g/mol = 0.883 mol
4) Volume proportion: 1 mol of gas at STP = 22.4 l
1 mol at STP 0.883 mol at STP
--------------------- = ------------------------------
22.4 l x
⇒ x = 0.883 mol × 22.4 l / 1 mol = 19.8 l ← answer
