The hypothesis gets proven wrong or right. The new information will either support the hypotheses or go against them.
Answer:
18 g
Explanation:
Step 1: Write the balanced equation
2 Al + 6 HCl ⇒ 2 AlCl₃ + 3 H₂
Step 2: Calculate the moles of Al
The molar mass of Al is 26.98 g/mol.
28.1 g × 1 mol/26.98 g = 1.04 mol
Step 3: Calculate the moles of HCl
46 mL of 1 M HCl react.
0.046 L × 1 mol/L = 0.046 mol
Step 4: Determine the limiting reactant
The theoretical molar ratio of Al to HCl is 2:6 = 0.33:1.
The real molar ratio of Al to HCl is 1.04:0.046 = 22.6:1
According to this, the limiting reactant is HCl.
Step 5: Calculate the mass of AlCl₃ generated from 0.046 moles of HCl
The molar ratio of HCl to AlCl₃ is 6:2. The molar mass of AlCl₃ is 133.34 g/mol.
0.046 mol HCl × 6 mol HCl/2 mol AlCl₃ × 133.34 g AlCl₃/1 mol AlCl₃ = 18 g AlCl₃
Answer: B
Explanation: its natural gas so its repleinishable
<span><span>A.) </span>makes it possible to
calculate ΔH for complicated chemical reactions </span>
<span>
Hess’s Law makes it
possible to calculate ΔH for complicated chemical reactions. Moreover, the principle
claims that the entire amount of “enthalpy” when the development or progression
of a chemical reaction is complete whether the reactions are created in a
single or numerous processes, it still changes. This law is now described as
the principle of conservation of energy, and part of the thermodynamics law as
the first. </span>
Answer:
a) 1,332 kJ are transferred
b) the temperature of the tree decreases 1.99 ºC
Explanation:
a) When a phase change occurs, the temperature remains constant for a pure substance, so, in this case, the heat transferred is:
Q = m*L, where m is the mass, and L is the latent heat, which for solidification of water is -333 kJ/kg:
Q = 4.00*(-333)
Q = -1332 kJ
So, 1,332 kJ are transferred.
b) If the amount of heat is transferred for the tree, and it has no phase change, it will receive a sensitive heat, which is:
Q = m*c*ΔT, where m is the mass, c is the specific heat, and ΔT the temperature change:
-1332 = 200*3.35*ΔT
670ΔT = -1332
ΔT = - 1.99 ºC
So the temperature of the tree decreases 1.99 ºC.