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3 years ago

Which element is a halogen?

2 answers:

8 0

Halogens are a group of elements found in the periodic table. They are the elements found in Group VIIA. It consists only of five chemical elements which are fluorine, chlorine, bromine, iodine and astatine. They are called as such because they are the salt formers.

garri49 [273]3 years ago

8 0

Answer: the group 7 includes fluorine (atomic symbol F), chlorine (atomic symbol Cl), bromine (atomic symbol Br), iodine (atomic symbol I), and astatine (atomic symbol At)

Explanation: Their reactivity decreases down the group. Halogens show different physical properties based on their positions in the periodic table. Physical properties include conductivity, electronegativity, melting and boiling points. All halogens are non-metals and are diatomic in the gaseous state. The non-metallic character decreases from fluorine to iodine

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Aqueous sulfuric acid reacts with solid sodium hydroxide to produce aqueous sodium sulfate and liquid water . If of water is pro

sergeinik [125]

The question is incomplete, here is the complete question:

Aqueous sulfuric acid reacts with solid sodium hydroxide to produce aqueous sodium sulfate and liquid water. If 12.5 g of water is produced from the reaction of 72.6 g of sulfuric acid and 77.0 g of sodium hydroxide, calculate the percent yield of water. Be sure your answer has the correct number of significant digits in it.

Answer: The percent yield of water in the reaction is 46.85 %.

Explanation:

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

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

For NaOH:

Given mass of NaOH = 77.0 g

Molar mass of NaOH = 40 g/mol

Putting values in equation 1, we get:

$\text{Moles of NaOH}=\frac{77.0g}{40g/mol}=1.925mol$

For sulfuric acid:

Given mass of sulfuric acid = 72.6 g

Molar mass of sulfuric acid = 98 g/mol

Putting values in equation 1, we get:

$\text{Moles of sulfuric acid}=\frac{72.6g}{98g/mol}=0.741mol$

The chemical equation for the reaction of NaOH and sulfuric acid follows:

$H_2SO_4+2NaOH\rightarrow Na_2SO_4+2H_2O$

By Stoichiometry of the reaction:

1 mole of sulfuric acid reacts with 2 moles of NaOH

So, 0.741 moles of sulfuric acid will react with = $\frac{2}{1}\times 0.741=1.482mol$ of NaOH

As, given amount of NaOH is more than the required amount. So, it is considered as an excess reagent.

Thus, sulfuric acid is considered as a limiting reagent because it limits the formation of product.

By Stoichiometry of the reaction:

1 mole of sulfuric acid produces 2 moles of water

So, 0.741 moles of sulfuric acid will produce = $\frac{2}{1}\times 0.741=1.482moles$ of water

Now, calculating the mass of water from equation 1, we get:

Molar mass of water = 18 g/mol

Moles of water = 1.482 moles

Putting values in equation 1, we get:

$1.482mol=\frac{\text{Mass of water}}{18g/mol}\\\\\text{Mass of water}=(1.482mol\times 18g/mol)=26.68g$

To calculate the percentage yield of water, we use the equation:

$\%\text{ yield}=\frac{\text{Experimental yield}}{\text{Theoretical yield}}\times 100$

Experimental yield of water = 12.5 g

Theoretical yield of water = 26.68 g

Putting values in above equation, we get:

$\%\text{ yield of water}=\frac{12.5g}{26.68g}\times 100\\\\\% \text{yield of water}=46.85\%$

Hence, the percent yield of water in the reaction is 46.85 %.

8 0

3 years ago

Butane and methyl propane are an example of a pair of

ELEN [110]

They are a pair of structural isomers because they both have the same chemical formula of C4H10 ingrained in each other

7 0

3 years ago

Read 2 more answers

Calculate the amount of heat required to completely sublime 28.0 g of solid dry ice (co2 at its sublimation temperature. the hea

lana66690 [7]

There is no need to do anything about the temperature, because sublimation does not involve any temperature change.

First, determine how many moles of CO2 there are. The mol. wt. of CO2 is 12 +2 x 16 = 44 g/mol.

So, 25.0 equals 25/44 = 0.568 moles

So the heat required is 0.568 mol x 32.3 KJ/mol = 18.3

4 0

3 years ago

Read 2 more answers

How many significant digits will the answer in the following calculations result in?

Reil [10]

Answer:

The answer will result in one significant digit.

Explanation:

1. Subtract:

12.1 - 12.004 = 0.096

2. ROund to the correct number of significant digits:

For addition and subtraction we round the sum or the difference to the least number of digits after the decimal point there are in the problem.

For example, SInce 12.1 has one number after the decimal point and 12.004 has three numbers after the decimal point, we round the answer to one number after the decimal point because 12.1 is the number in the problem which has the least amount of digits after the decimal point.

We round 0.096 to 0.1.

0.1 has one significant digit.

7 0

3 years ago

How does genetic variation play a role in evolution? I give Brainless

Setler79 [48]

Answer:

Evolution is the process by which populations of organisms change over generations. Genetic variations underlie these changes

Explanation:

If a trait is advantageous and helps the individual survive and reproduce, the genetic variation is more likely to be passed to the next generation.

Brain-List?

4 0

3 years ago