Answer: adding
Explanation:
Because it takes thermal energy to power it
The answer is A, a new chemical substance has to be formed for there to be a chemical change. This is because chemical change happens when a phase of matter changes due to chemicals.
The second one is correct. Alleles on homologous chromosomes determine traits
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
P1V1 = P2V2
P1 = 720 mmHg
V1 = 450. mL
P2 = 760 mmHg (this is the pressure at STP)
Use these to solve for V2:
(720)(450) = 760V2
V2 = 426 mL