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3 years ago

Please help witht 4 and 5

Chemistry

2 answers:

Effectus [21]3 years ago

3 0

Answer:

that would be 32 and then the other one would be 7,000

Crazy boy [7]3 years ago

3 0

Answer:

#4: 0.89 mol/L #5: 0.36 mol

Explanation:

#4: Morality is Moles/ Liters

So take 3.2 mols ÷ 3.6 L = 0.8888... since there are 2 sig figs in the question the answer would round to 0.89 mol/L

#5: to find the number of moles needed, you take the mol/L and multiply that by the volume.

0.89 mol/L ×0.400L = 0.356 mols. the liters cancel out. Since 0.89 has the least number of sig figs your final answer should have 2. which it 0.36 mols.

I hope this helps, good luck!

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HELP NOW!!!!!! When you put water into a hot metal pan of equal mass, why does the pan cool down more than the water heats up?

Salsk061 [2.6K]

Answer:

Because the specific heat of the metal is less than the specific heat of water.

Explanation:

Hello, happy to help you today!

In this case, we need to analyze a property called "specific heat" which accounts for how much energy is required to increase or decrease the temperature of 1 g of the substance by 1 °C.

In this case, since the specific heat of water is about 4.184 J/g°C and the specific heat of metals in general is greater than zero, of course, but less than one, we can infer that for the same amount of energy, when they are in contact, more grams of metal will be cooled down to those of water heated up, because the specific heat of the metal is less than the specific heat of water.

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8 0

3 years ago

If 7.50 g of the unknown compound contained 0.250 mol of c and 0.500 mol of h, how many moles of oxygen, o, were in the sample?

Mice21 [21]

It would be 100.60 because we're adding like to the atmosphere it connects to lubricator and then it turns so that's 100.60

3 0

3 years ago

Liquid octane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water . Suppose 97. g of octane is mi

zhannawk [14.2K]

Answer: 61 grams

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles of octane}=\frac{\text{Given mass}}{\text{Molar mass}}=\frac{97g}{114g/mol}=0.85moles$

$\text{Number of moles of oxygen}=\frac{\text{Given mass}}{\text{Molar mass}}=\frac{150g}{32g/mol}=4.69moles$

The chemical equation for the combustion of octane in oxygen follows the equation:

$2C_8H_{18}+25O_2\rightarrow 16CO_2+18H_2O$

By stoichiometry of the reaction;

25 moles of oxygen react with 2 moles of octane

4.69 moles of oxygen react with= $\frac{2}{25}\times 4.69=0.37$ moles of octane

Thus, oxygen is the limiting reagent as it limits the formation of product and octane is the excess reagent.

25 moles of oxygen produce 18 moles of water

4.69 moles of oxygen produce= $\frac{18}{25}\times 4.69=3.38$ moles of water.

Mass of water produced= $moles\times {\text{Molar mass}}=3.38\times 18g/mol=61g$

The maximum mass of water that could be produced by the chemical reaction is 61 grams.

6 0

3 years ago

Tetrahydrocannabinol (thc) is composed of 80.24% carbon, 9.62% hydrogen and 10.14% oxygen by mass. what is the empirical formula

Alika [10]

80.24% carbon, 9.62% hydrogen and 10.14% oxygen

1) Base: 100 g

C: 80.24 g
H: 9.62 g
O: 10.14 g
----------
100.00 g

2) Conversion to moles

C: 80.24 g / 12.00 g /mol = 6.687 mol
H: 9.62 g / 1.00 g/mol = 9.62 mol
O: 10.14 g / 16.00 g/mol = 0.63375 mol

3) Ratio

C:6.687 / 0.63375 = 10.55
H: 9.62 / 0.63375 = 15.18
O: 0.63375 / 0.63375 = 1

Given that the tenth of C is 0.5 you need to multiply all the numbers by 2 =>

C: 10.55 * 2 = 21.1--> 21
H: 15.18 * 2 = 30.36 -> 30
O: 1 * 2 = 2

=> C21 H30 O2

Answer: C21 H30 O2

7 0

3 years ago

Which of the following elements does NOT form a diatomic molecule? Question 5 options: H2 O2 Mg2 Br2

erica [24]

Mg is a metal. Under ordinary conditions it will not form a diatomic molecule. The other 3 are non metals. They come from the right side of the periodic table and they willl form diatomic molecules.

6 0

4 years ago