the answer is A.) the moon is orbiting the earth once per month
its the only logical answer, the others are either impossible or illogical
Answer:
a. qm = 627.3 J
b. qw = 627.3 J
c. C₂ = 227.4 J/kg.°C
Explanation:
a.
Since, the calorimeter is completely insulated. Therefore,
Heat Lost by Metal = Heat Gained by water
qm = qw
qm = m₁C₁ΔT₁
where,
qm = heat lost by metal = ?
m₁ = mass of water = (density)(volume) = (1000 kg/m³)(100 mL)(10⁻⁶ m³/1 mL)
m₁ = 0.1 kg
C₁ = specific heat capacity of water = 4182 J/kg.°C
ΔT₁ = Change in Temperature of Water = 19.1°C - 17.6°C = 1.5°C
Therefore,
qm = (0.1 kg)(4182 J/kg.°C)(1.5°C)
<u>qm = 627.3 J</u>
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b.
Since,
qm = qw
<u>qw = 627.3 J</u>
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c.
qm = m₂C₂ΔT₂
where,
m₂ = mass of metal = 38.1 g = 0.0381 kg
C₂ = specific heat capacity of metal = ?
ΔT₂ = Change in Temperature of metal = 90°C - 17.6°C = 72.4°C
Therefore,
627.3 J = (0.0381 kg)(C₂)(72.4°C)
(627.3 J)/(0.0381 kg)(72.4°C) = C₂
<u>C₂ = 227.4 J/kg.°C</u>
Answer:
2.00 × 10⁻³ g
Explanation:
Step 1: Write the balanced decomposition reaction
2 NaHCO₃ ⇒ Na₂CO₃ + CO₂ + H₂O
Step 2: Calculate the moles corresponding to 0.0118 g of Na₂CO₃
The molar mass of Na₂CO₃ is 105.99 g/mol.
0.0118 g × 1 mol/105.99 g = 1.11 × 10⁻⁴ mol
Step 3: Calculate the moles of H₂O produced with 1.11 × 10⁻⁴ moles of Na₂CO₃
The molar ratio of Na₂CO₃ to H₂O is 1:1. The moles of H₂O produced are 1/1 × 1.11 × 10⁻⁴ mol = 1.11 × 10⁻⁴ mol.
Step 4: Calculate the mass corresponding to 1.11 × 10⁻⁴ moles of H₂O
The molar mass of H₂O is 18.02 g/mol.
1.11 × 10⁻⁴ mol × 18.02 g/mol = 2.00 × 10⁻³ g
Answer: 3.0 moles of water
are needed to react with a mole of 3.0 of Na
Explanation:
The balanced chemical reaction of sodium with water is as follows:

According to stoichiometry:
2 moles of sodium
reacts with = 2 moles of water 
Thus 3.0 moles of sodium
reacts with =
moles of water 
3.0 moles of water
are needed to react with a mole of 3.0 of Na
Answer:
D.) molecule
<h3>When the same or different atoms combine together they for a molecule</h3>