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3 years ago

According to recent research, ice skaters are able to glide smoothly across the ice because _____.

1 answer:

5 0

Friction because smooth ice provides very little resistance against objects, like ice skates being dragged across its surface.

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Enter your answer in the provided box. To make use of an ionic hydrate for storing solar energy, you place 409.0 kg of sodium su

alex41 [277]

Answer:

409.0 kg of sodium sulfate decahydrate will produce 4.49×10⁵ kJ

of heat energy.

Explanation:

CHECK THE COMPLETE QUESTION BELOW

To make use of an ionic hydrate for storing solar energy, you place 409.0 kg of sodium sulfate decahydrate on your house roof. Assuming complete reaction and 100% efficiency of heat transfer, how much heat (in kJ) is released to your house at night? Note that sodium sulfate decahydrate will transfer 354 kJ/mol

EXPLANATION

Here we were asked to calculate the amount of heat will be generated by 409.0 kg of sodium sulfate decahydrate at night assuming there Isa complete reaction and 100% efficiency of heat transfer in the process

The molecular weight of sodium sulfate decahydrate (H₂₀Na₂O₁₄S) is needed here, so it must be firstly calculated.

The molecular weight of sodium sulfate decahydrate (H₂₀Na₂O₁₄S)

( 1*20) + (22.98*2) + (16*14)+ (32*14)= 322.186 g/mol.

Thus 409.0 kg of H₂₀Na₂O₁₄S will have a value which is equivalent to = (409000g)/(322.186 g/mol.)

=1269.453mol of H₂₀Na₂O₁₄S.

But it was stated in the the question that per mole of H₂₀Na₂O₁₄S will transfer 354 kJ heat.

Therefore, 1269.453mol will transfer 1269.453× 354 kJ = 4.49×10⁵ kJ of heat.

Hence, 409.0 kg of sodium sulfate decahydrate will produce

4.49×10⁵ kJ of heat energy.

6 0

3 years ago

. KMnO4 oxidizes ethyl benzene to benzoic acid. If this reaction generally results in a 40 % experimental yield, how many grams

lyudmila [28]

Answer:

530.835 g

Explanation:

First we convert 244 g of benzoic acid (C₇H₆O₂) to moles, using its molar mass:

244 g benzoic acid ÷ 122.12 g/mol = 2.00 moles benzoic acid

Theoretically,<em> one mol of ethyl benzene would produce one mol of benzoic acid</em>. But the experimental yield tells us that one mol of ethyl benzene will produce only 0.4 moles of benzoic acid.

With the above information in mind we convert 2.00 moles of benzoic acid into moles of ethyl benzene:

2.00 moles benzoic acid * $\frac{1molEthylBenzene}{0.4molBenzoicAcid}$ = 5.00 moles ethyl benzene

Finally we <u>convert moles of ethyl benzene </u>(C₈H₁₀)<u> into grams</u>, using its <em>molar mass</em>:

5.00 moles ethyl benzene * 106.167 g/mol = 530.835 g ethyl benzene

7 0

3 years ago

What is the molecular shape of N2O2?

Anettt [7]

Answer:

If you're just looking at the Lewis Structure from the perspective of the octet rule, it does appear that the structure is correct. Dinitrogen always has a lone pair of electrons which could conceivably be used for dative bonding as you suggest. So from that perspective there appears to be nothing wrong at all - other than that it doesn't exist in nature in this way.

Explanation:

3 0

3 years ago

Last year Steve was shorter than his brother. This year Steve is taller than his brother. What cell process is directly responsi

lutik1710 [3]

Answer:

he drank milk!!!

Explanation:

1. he told his dad to go get the milk

2. Steve's dad didn't come back until a year!

3. Steve's dad came back and gave him milk!

4. and boom, he grew!!