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3 years ago

When 69.9 g heptane is burned it releases __ mol water.

Chemistry

1 answer:

professor190 [17]3 years ago

5 0

Answer:

1) When 69.9 g heptane is burned it releases 5.6 mol water.

2) C₇H₁₆ + 11O₂ → 7CO₂ + 8H₂O.

Explanation:

Firstly, we should balance the equation of heptane combustion.

The balanced equation is: C₇H₁₆ + 11O₂ → 7CO₂ + 8H₂O.

This means that every 1.0 mole of complete combustion of heptane will release 8 moles of H₂O.

We need to calculate the no. of moles in 69.9 g of heptane that is burned using the relation: n = mass/molar mass.

n of 69.9 g of heptane = mass/molar mass = (69.9 g)/(100.21 g/mol) = 0.697 mol ≅ 0.7 mol.

Using cross multiplication:

1.0 mol of heptane releases → 8 moles of water.

0.7 mol of heptane releases → ??? moles of water.

∴ The no. of moles of water that will be released from burning (69.9 g) of water = (0.7 mol)(8.0 mol)/(1.0 mol) = 5.6 mol.

∴ When 69.9 g heptane is burned it releases 5.6 mol water.

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What is the minimum (non-zero) thickness of a benzene (n = 1.501) thin film that will result in constructive interference when v

ad-work [718]

Explanation:

At each reflecting surface (benzene and glass) there will be 180 degree phase change.

Now, for constructive interference the optical path in benzene is $\lambda$ .

Formula to calculate thickness of a benzene thin film is as follows.

Optical path length through benzene ( $\lambda$ ) = $2 \times n \times d$

Hence, substituting the given values into the above formula as follows.

Optical path length through benzene = $2 \times n \times d$

d = $\frac{\text{Optical path length through benzene}}{2 \times n}$

= $\frac{\lambda}{2 \times n}$

= $\frac{615 \times 10^{-9}}{2 \times 1.501}$ (as 1 nm = $10^{-9}m$

= 204.9 m

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3 years ago

Tom lost money on his peach crops because they kept freezing in the winter. How could Tom most likely solve the problem of his p

vova2212 [387]

Answer:

B. He could breed his peach plants with peach plants that can survive the frost.

Explanation:

Tom can best solve his problem by breeding his peach plants with the ones that can survive the frost.

This is known cross breeding
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If Tom can cross breed the failing peaches with the successful winter resistant ones, he can ensure better production.
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3 years ago

If the [H+] in a solution is 1 × 10–1 mol/L, what is the [OH–]? Show your work.

AVprozaik [17]

Hello!

The basic equations to solve this is
pH = -log[H+]
pOH = -log[OH-]
pH + pOH = 14
------------------------------------------------------------------------------------------------------
Find pH

pH = -log(1 * 10^-1)
pH = 1
------------------------------------------------------------------------------------------------------
Find pOH
1 + pOH = 14

pOH = 13
------------------------------------------------------------------------------------------------------
Find OH-
[OH-] = 10^(-pOH)
[OH-] = 1 * 10^-13mo/L

The answer is $[OH-] = 1 * 10^{-13} mol/L$

Hope this helps!

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vesna_86 [32]

Answer: 1.07×10^-20microlitre

Explanation:

1cm3 = 1000microlitres

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3 years ago

Consider the reaction when aqueous solutions of chromium(III) chloride and ammonium sulfide are combined. The net ionic equation

Dominik [7]

Answer:

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3 years ago