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3 years ago

Suggest a method for measuring the size of the colony.

Chemistry

1 answer:

Evgen [1.6K]3 years ago

7 0

Answer:

Counting the number of colonies that arise on a pour plate can calculate the concentration by multiplying the count by the volume spread on the pour plate. Direct counting methods are easy to perform and do not require highly specialized equipment, but are often slower than other methods

Explanation:

I hope it will help you

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A gas mixture of Ne and Ar has a total pressure of 4.00 atm and contains 16.0 mol of gas. If the partial pressure of Ne is 2.75

Stolb23 [73]

Answer:

5 moles of Argon is present in the mixture.

Explanation:

Total pressure of the gaseous mixture = 4 atm

Total number of moles = 16

Partial pressure of Ne = 2.75 atm

By Dalton's law of partial pressure, the total pressure of gaseous mixture is the sum of partial pressures of individual gases which are non-reactive.

Hence:

$P_{total}=P_{Ar}+P_{Ne}\\4=P_{Ar}+2.75\\P_{Ar}=1.25\ atm$

Also :

Partial pressure = mole fraction*total pressure

$P_{Ar}=X_{Ar}P_{total}$

$X_{Ar}=\frac{1.25}{4}=0.3125$

$\frac{n_{Ar}}{n_{total}}=0.3125\\n_{Ar}=5$

∴Number of moles of Argon = 5

4 0

4 years ago

If the pressure exerted by a gas at 100 Celsius in a volume of 0.044 L is 3.81 atm, how many maples of gas are present

Vera_Pavlovna [14]

The number of moles of gas present are 0.0054

Explanation:

Given-

Temperature, T = 100°C = 100 + 273 = 373K

Volume, V = 0.044L

Pressure, P = 3.81 atm

Moles of gas, n = ?

We know,

PV = nRT

R = 0.082 L.atm.K⁻¹.mol⁻¹

n = PV/RT

n = (3.81)(0.044)/(0.082)(373)

n = 0.0054 moles

Therefore, number of moles of gas present are 0.0054

7 0

3 years ago

Hydrazine, , emits a large quantity of energy when it reacts with oxygen, which has led to hydrazine used as a fuel for rockets:

Tcecarenko [31]

Answer:

$1.25~mol~H_2O$ and $0.627~mol~N_2$

Explanation:

Our goal for this question is the calculation of the number of moles of the molecules produced by the reaction of hydrazine ( $N_2H_4$ ) and oxygen ( $O_2$ ). So, we can start with the reaction between these compounds:

$N_2H_4~+~O_2~->~N_2~+~H_2O$

Now we can balance the reaction:

$N_2H_4~+~O_2~->~N_2~+~2H_2O$

In the problem, we have the values for both reagents. Therefore we have to calculate the limiting reagent. Our first step, is to calculate the moles of each compound using the molar masses values (32.04 g/mol for $N_2H_4$ and 31.99 g/mol for $O_2$ ):

$20.1~g~N_2H_4\frac{1~mol~N_2H_4}{32.04~g~N_2H_4}=0.627~mol~N_2H_4$

$20.1~g~O_2\frac{1~mol~O_2}{31.99~g~O_2}=0.628~mol~O_2$

In the balanced reaction we have 1 mol for each reagent (the numbers in front of $O_2$ and $N_2H_4$ are 1). Therefore the smallest value would be the limiting reagent, in this case, the limiting reagent is $N_2H_4$ .

With this in mind, we can calculate the number of moles for each product. In the case of $N_2$ we have a 1:1 molar ratio (1 mol of $N_2$ is produced by 1 mol of $N_2H_4$ ), so:

$0.627~mol~N_2H_4\frac{1~mol~N_2}{1~mol~N_2H_4}=~0.627~mol~N_2$

We can follow the same logic for the other compound. In the case of $H_2O$ we have a 1:2 molar ratio (2 mol of $H_2O$ is produced by 1 mol of $N_2H_4$ ), so:

$0.627~mol~N_2H_4\frac{2~mol~H_2O}{1~mol~N_2H_4}=~1.25~mol~H_2O$

I hope it helps!

4 0

4 years ago

Write a paragraph, citing examples from the text, to explain how Dr.

grigory [225]

Paul J. Chirik developed methods associated with chemistry catalysis and transition metals, which may result useful for the development of manufacturing technologies.

<h3>What is catalysis?</h3>

Catalysis refers to the chemical processes that increase the rate of different types of reactions by lowering its activation energy.

Proteins (enzymes) are biological catalysts that increase the rate of chemical reactions in biological systems.

Catalysis may be reached by using transition metals (e.g., actinium and rutherfordium), which result useful in the development of manufacturing technologies.

Learn more about catalysis here:

brainly.com/question/12507566

8 0

2 years ago

I need help on my chemistry quiz

slamgirl [31]

Answer:

it could be 25degrees c... not sure

4 0

3 years ago