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2 years ago

How many molecules Of H20 are equivalent to 97.2 g H20? (H = 1.008 g/mol, O = 16.00 g/mol)

Chemistry

1 answer:

AleksandrR [38]2 years ago

8 0

Answer:

m(H₂O) = 97,2 g.n(H₂O) = m(H₂O) ÷ M(H₂O).n(H₂O) = 97,2 g ÷ 18

Explanation:

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Stearic acid (C18H36O2) is a fatty acid, a molecule with a long hydrocarbon chain and an organic acid group (COOH) at the end. I

Paha777 [63]

Answer:

There is 9671 Kj of heat released

Explanation:

Step 1: The balanced equation:

C18H36O2(s) + 26O2(g) --> 18CO2(g)+18H2O(g)

This means for 1 mole of C18H36O2 consumed there is 26 moles of O2 needed to produce 18 moles of CO2 and 18 moles of H2O.

Step 2: Calculate the heat of combustion

ΔH (combustion) = [18*(ΔHf of CO2) + 18*(ΔHf of H2O)] - [1*(ΔHf of C18H36O2) + 26*(ΔHf of O2)]

ΔH (combustion) = [18*(-394 kJ/mol) + 18*(-242 kJ/mol)] - [1*(-948 kJ/mol) + 26*(0 kJ/mol)]

ΔH (combustion) = [(-7092 kJ/mol) + (-4356 kJ/mol)] - (-948 kJ/mol)

= -10500 kJ/mol

ΔH (combustion) = heat released / number of moles of stearic acid

Step 3: Calculate moles of stearic acid

moles of stearic acid = mass / Molar mass of stearic acid

moles of stearic acid = 262g / 284.48 g/mole = 0.921 moles

Step 4: Calculate moles of oxygen

moles of O2 = 914.5 / 32g/mole

moles of O2 = 28.578125 moles

Stearic acid is the limiting reactant: it will completely react

There will react 26*0.921 mole = 23.946 mole of O2

This means there will remain 4.63 moles of O2

Step 5: Calculate heat released

q = (ΔH combustion) * (moles of stearic acid) = (-10500 kJ/mol) * (0.921 moles) = 9671 Kj

There is 9671 Kj of heat released

6 0

3 years ago

What year will Aquarius be visible from Earth’s North Pole?

Minchanka [31]

Answer:

Aquarius beginning in the mid-3rd millennium. The north and south celestial poles are the two imaginary points in the sky where the Earth's ... In about 5,500 years, the pole will have moved near the position of the star ... The south celestial pole is visible only from the Southern Hemisphere.

Explanation:

3 0

3 years ago

The book procedure calls for 2,5-dimethylhexane-2,5-diol and concentrated hydrochloric acid to be shaken in a reaction vial. Whi

san4es73 [151]

Answer:

E) All of the above.

Explanation:

Hello,

Since the acidic nature of the HCl implies its corrosiveness, when it is in contact with the skin and eyes the burning starts immediately, so gloves and goggles must be worn. Next, the fuming hydrochloric acid (37% by mass) is volatile so it gives off even when dissolved into water, so it must be used in the fume hood. Then, since vapors are produced during the chemical reaction, an overpressure could be attained, that's why we must keep the glass sash of the fume hood between us and the vial. As a common risk, the vial could be dropped causing the hydrochloric acid to splash, so we must keep the vial well inside the hood.

Best regards.

7 0

3 years ago

Which of these statements are true? Select all that apply.

777dan777 [17]

Answer:

The AH+ for Br2() is 0 kJ/mol.

The AH+ for Hg() is 0 kJ/mol.

The AH; for N261) is 0 kJ/mol.

Explanation:

7 0

2 years ago

snow_tiger [21]

There are 1,000m is 1k. So just move the decimal one position right. 127.56m

There are 10,000cm in 1k. Move the decimal two positions right. 1275.6cm

5 0

3 years ago