Answer: See below
Explanation:
1. a) 0.15 moles calcium carbonate (15g/100g/mole)
b) 0.15 moles CaO (molar ratio of CaO to CaCO3 is 1:1)
c) 8.4 grams CaO (0.15 moles)*(56 grams/mole)
2. a) 0.274 moles Na2O (17g/62 grams/mole)
b) 46.6 grams NaNO3 (2 moles NaNO3/1 mole Na2O)*(0.274 moles Na2O)*(85 g/mole NaNO3)
No' of molecules divide by avogadro number , 6×6.023×10^23 so (2.2×10^22)÷(6.023×10^23)
= 0.03653 moles
moles × Molar mass = mass
n×Mr=m
0.03653×40 = 1.46 grams
The correct answer to the problem is 0.193 which is three significant figures.
<h3>What are significant figures?</h3>
The term significant figures has to do with the figures that have a mathematical meaning. We know that the result has to correspond to the highest number of significant figures.
Hence, If we multiply 0.34 x 0.568 the result ought to be recorded as 0.193 which is three significant figures.
Learn more about significant figures:brainly.com/question/14804345
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Answer:
B) The metal temperature changed more than the water temperature did, but the metal lost
the same amount of thermal energy as the water gained.
Explanation:
Heat capacity or thermal capacity is defined as the amount of heat required by a given mass of a material to raise its temperature by one unit which means that the heat capacity of the water, that is the quantity of heat required to cause a rise from 22°C to 35°C that is a rise of 13°C is the quantity of heat that caused the drop in temperature of the metal from 100°C to 35°C a change of 65°C
The water has more capacity to absorb heat or a higher heat capacity than the metal
However, the first law of thermodynamics states that energy is neither created nor destroyed, but it changes from one form to another. In this case, the thermal energy lost by the metal is the same as the thermal or heat energy gained by the water
The combustion reaction of octane is as follow,
C₈H₁₈ + 25/2 O₂ → 8 CO₂ + 9 H₂O
According to balance equation,
8 moles of CO₂ are released when = 114.23 g (1 mole) Octane is reacted
So,
6.20 moles of CO₂ will release when = X g of Octane is reacted
Solving for X,
X = (114.23 g × 6.20 mol) ÷ 8 mol
X = 88.52 g of Octane
Result:
88.52 g of Octane is needed to release 6.20 mol CO₂.
