Which descriptions apply to eukaryotic cells? Check all that apply.

What is science?

nikdorinn [45]

A body of knowledge and a process of gaining that knowledge

4 0

2 years ago

The molar mass of c3h8o2 (four significant figures) is ________.

Luda [366]

So carbon is 12(3), hydrogen is 1.01 (8), and oxygen is 16(2). Add it all together and you get 76.08 amu. That's molecular. The molar would be in grams (76.08 g). Hope that answered the question.

6 0

2 years ago

A sample of 508.4 grams of copper completely reacted with oxygen to form 572.4 grams of a copper oxide product. how many grams o

Svet_ta [14]

According to law of conservation of mass, mass can neither be destroyed nor created in a chemical reaction. Thus, sum of masses of reactants must be equal to sum of masses of products in a reaction.

The chemical reaction is as follows:

$2Cu+O_{2}\rightarrow 2CuO$

Here, sum of masses of Cu and oxygen gas should be equal to CuO formed.

$2m_{Cu}+m_{O_{2}}=2m_{CuO}$

Thus, mass of oxygen will be:

$m_{O_{2}}=2(572.4-508.4)g=128 g$

This can be further proved as follows:

The balanced chemical reaction is as follows:

$2Cu+O_{2}\rightarrow 2CuO$

Here, 2 moles of Cu completely reacts with 1 mole of $O_{2}$ to give 2 moles of $CuO$ .

Thus, 1 mole of Cu reacts with 0.5 moles of $O_{2}$ .

The mass of Cu is 508.4 and molar mass is 63.546 g/mol, number of moles can be calculated as follows:

$n=\frac{m}{M}=\frac{508.4 g}{63.546 g/mol}=8 mol$

Thus, number of moles of $O_{2}$ reacting will be:

$n_{O_{2}}=8\times 0.5 mol=4 mol$

Molar mass of oxygen molecule is 32 g/mol thus, mass can be calculated as follows:

m=n×M=4 mol×32 g/mol=128 g/mol

This satisfies the law of conservation of mass.

7 0

2 years ago

What is the maximum number of grams of ammonia, nh3, which can be obtained from the reaction of 10.0 g of h2 and 80.0 g of n2? n

Lelechka [254]

Answer: The mass of ammonia produced is 28.22 g

Explanation:

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

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

For hydrogen gas:

Given mass of hydrogen gas = 10.0 g

Molar mass of hydrogen gas = 2 g/mol

Putting values in equation 1, we get:

$\text{Moles of hydrogen gas}=\frac{10.0g}{2g/mol}=5mol$

For nitrogen gas:

Given mass of nitrogen gas = 80.0 g

Molar mass of nitrogen gas = 28 g/mol

Putting values in equation 1, we get:

$\text{Moles of nitrogen gas}=\frac{80.0g}{28g/mol}=2.86mol$

The given chemical equation follows:

$N_2+3H_2\rightarrow 2NH_3$

By Stoichiometry of the reaction:

3 moles of hydrogen gas reacts with 1 mole of nitrogen gas

So, 5 moles of hydrogen gas will react with = $\frac{1}{3}\times 5=1.66mol$ of nitrogen gas

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

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

By Stoichiometry of the reaction:

3 moles of hydrogen gas produces 1 mole of ammonia

So, 5 moles of hydrogen gas will produce = $\frac{1}{3}\times 5=1.66moles$ of ammonia

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

Molar mass of ammonia = 17 g/mol

Moles of ammonia = 1.66 moles

Putting values in equation 1, we get:

$1.66mol=\frac{\text{Mass of ammonia}}{17g/mol}\\\\\text{Mass of ammonia}=(1.66mol\times 17g/mol)=28.22g$

Hence, the mass of ammonia produced is 28.22 g

4 0

2 years ago

Driving cars lowers the pH of the oceans by _______.

Anna [14]

Correct answer: a. releasing CO2 that dissolves and forms acid in the oceans

The fuels used in automobiles release gases like carbon dioxide, carbon monoxide, oxides of nitrogen and sulfur. Carbon dioxide when dissolved in water forms carbonic acid. So, when the usage of cars is high, these emissions of carbon-dioxide into the atmosphere increase and this leads to the lowering of pH of the oceans as the carbon dioxide present in higher amounts in to atmosphere diffuses into the oceanic waters and form carbonic acid which makes the ocean slightly acidic.

$CO_{2}(g) + H_{2}O (l) H_{2}CO_{3}(aq)$

6 0

2 years ago

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