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3 years ago

What is measured by the heat of reaction?

Chemistry

1 answer:

bixtya [17]3 years ago

6 0

Answer:

The heat of reaction is basically the energy that is being released and or absorbed when chemicals are transformed in a type of chemical reaction. However, the heat of reaction or also called reaction enthalpy is mostly or typically expressed as a molar enthalpy in kJ/mol and or as just a specific enthalpy in kJ/kg or kJ/L.

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How many grams of carbon monoxide are needed to react with an excess of iron (III) oxide to produce 198.5 grams of iron? Fe2O3(s

erastova [34]

Answer : The grams of carbon monoxide needed are 148.89 g

Solution : Given,

Mass of iron, Fe = 198.5 g

Molar mass of iron, Fe = 56 g/mole

Molar mass of carbon monoxide, CO = 28 g/mole

First we have to calculate the moles of iron, Fe.

$\text{ Moles of Fe}=\frac{\text{ Mass of Fe}}{\text{ Molar mass of Fe}}=\frac{198.5g}{56g/mole}=3.545moles$

The balanced chemical reaction is,

$Fe_2O_3(s)+3CO(g)\rightarrow 3CO_2(g)+2Fe(s)$

From the balanced reaction, we conclude that

2 moles of iron produces from the 3 moles of carbon monoxide

3.545 moles of iron produces from the $\frac{3}{2}\times 3.545=5.3175$ moles of carbon monoxide

Now we have to calculate the mass of carbon monoxide, CO.

$\text{ Mass of CO}=\text{ Moles of CO}\times \text{ Molar mass of CO}$

$\text{ Mass of CO}=(5.3175moles)\times (28g/mole)=148.89g$

Therefore, the grams of carbon monoxide needed are 148.89 g

7 0

3 years ago

Which family on the periodic table has a filled outer energy level?

Ede4ka [16]

The family on the periodic table that has a filled outer energy level is VIIIA. The answer is letter D. They are also called the noble gases or inert gases. They are virtually unreactive towards other elements or compounds. They are found in trace amounts in the atmosphere. Their elemental form at room temperature is colorless, odorless and monatomic gases. They also have full octet of eight valence electrons in their highest orbitals so they have a very little tendency to gain or lose electrons to form ions or share electrons with other elements in covalent bonds.

6 0

4 years ago

Four acids are analyzed and there KA values are determined which of the following values represents the strongest acid

Advocard [28]

x= the coefficients in front of the substance in the balanced chemical equation

[H+]= the concentration of hydrogen ions

[A-]= the concentration of the other ion that broke off from the H+

[HA]= the un-disassociated acid concentration

The higher the Ka value, the greater amount of disassociation of the reactants into products. As for acids, they will break down to form H+ ions. The more the H+ ions, the stronger acidity of the solution. Thus since A has the highest Ka value, that represents the strongest acid.

You can determine the Ka value from a number of ways. If equilibrium concentrations are given of a certain acid solution, you can find the proportion of the concentration of ions to the concentration of the remaining HA molecules, using the equation above. Also, pH and KpH can be used in a number of ways. This gets more complicated and depends on the situation, and requires more advanced equations.

Hope this helped a little, its obviously not my best work

6 0

4 years ago

Read 2 more answers

The Nutrition Facts label for crackers states that one serving contains 19 g of carbohydrate, 4 g of fat, and 2 g of protein. Wh

sp2606 [1]

Answer: The amount of kilocalories contained in the given serving of crackes is 0.120 kCal

Explanation:

As per the USDA:

Carbohydrates provide 4 calories per gram, protein provides 4 calories per gram, and fat provides 9 calories per gram

We are given:

Mass of fat in the crackers = 4 g

Mass of carbohydrates in the crackers = 19 g

Mass of protein in the crackers = 2 g

Conversion factor used: 1 kCal = 1000 Cal

Applying unitary method:

For Fat:

1 gram of fat provides 9 calories

So, 4 gram of fat will provide = $\frac{9}{1}\times 4=36Cal=0.036kCal$

For Carbohydrates:

1 gram of carbohydrates provides 4 calories

So, 19 gram of carbohydrates will provide = $\frac{4}{1}\times 19=76Cal=0.076kCal$

For Proteins:

1 gram of proteins provides 4 calories

So, 2 gram of fat will provide = $\frac{4}{1}\times 2=8Cal=0.008kCal$

Total kilocalories per serving = [0.036 + 0.076 + 0.008] kCal = 0.120 kCal

Hence, the amount of kilocalories contained in the given serving of crackes is 0.120 kCal

8 0

3 years ago

Is a situation in which a dominant allele completely masks a recessive allele for a gene.

Bond [772]

Complete dominance.... Hope this helps

4 0

3 years ago