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3 years ago

A) Which of the following equations model the law of conservations of mass? Ca + 2HCI - H2 + CaCl2 or

Chemistry

1 answer:

nydimaria [60]3 years ago

4 0

Answer:

The first equation

Explanation:

For these problems, it is best to label and record how many of each element are on each side of the equation. The first equation has 1 Ca, 2H, and 2Cl on both sides while the second equation has 3H on the left and 2H on the right making the second equation incorrect.

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What happens if a species is unable to adapt to a changing environment.

enot [183]

The awnser your looking for would be B: It's Population decreases. Because if a species is unable to adapt to a changing environment the species would either have to move away or they could die in that location.

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3 years ago

Modify isoleucine, below, to show its structure at pH 1 and pH 13.

NeTakaya

I have attached the answer

remember that when the solution is acidic, pH lower than 7. there are extra H+ that the amino acid can take. the basic part of the amino acid takes this extra hydrogen (the nitrogen).

when the pH is higher than 7, basic, there are not much H+ available. the amino acid loses a H+. the acid part of the amino acid loses the H (the carboxylic part).

7 0

3 years ago

Hydrogen chloride gas and oxygen gas react to form water and chlorine gas. A reaction mixture initially contains 53.2 g of hydro

Sergio [31]

Answer: The mass of the excess reactant (oxygen gas) is 3.136 grams

Explanation:

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

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

For HCl:

Given mass of HCl = 53.2 g

Molar mass of HCl = 36.5 g/mol

Putting values in equation 1, we get:

$\text{Moles of HCl}=\frac{53.2g}{36.5g/mol}=1.46mol$

For oxygen gas:

Given mass of oxygen gas = 26.5 g

Molar mass of oxygen gas = 32 g/mol

Putting values in equation 1, we get:

$\text{Moles of oxygen gas}=\frac{26.5g}{32g/mol}=0.828mol$

The chemical equation for the reaction of HCl and oxygen gas follows:

$2HCl+O_2\rightarrow H_2O+Cl_2$

By Stoichiometry of the reaction:

2 moles of HCl reacts with 1 mole of oxygen gas

So, 1.46 moles of HCl will react with = $\frac{1}{2}\times 1.46=0.73mol$ of oxygen gas

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

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

Excess moles of oxygen gas = (0.828 - 0.73) = 0.098 moles

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

Molar mass of oxygen gas = 32 g/mol

Excess moles of oxygen gas = 0.098 moles

Putting values in equation 1, we get:

$0.098mol=\frac{\text{Mass of oxygen gas}}{32g/mol}\\\\\text{Mass of oxygen gas}=(0.098mol\times 32g/mol)=3.136g$

Hence, the mass of the excess reactant (oxygen gas) is 3.136 grams

4 0

3 years ago

PLEASE I WILL RATE YOU AND I DONT HAVE TIME PLEASEEE The volume of a substance is 20cm³ and its mass is 80 gm. Will this substan

kotykmax [81]

Answer:

80g=0.08kg

20cm=0.02m

density=m/v

= 0.08/0.02

=4kg/m^3

it is less than density of water so it floats

4 0

3 years ago

Which statements are true concerning our interpretation of the results of an experiment?

miskamm [114]

Answer:

3. Judgement may be affected by what we already think is true (prior knowledge).

Explanation:

This statement is the correct answer because someone could be bias. Due to biases, prior knowledge may be incorrect and our conclusion may be wrong if you don't focus on the data given.

7 0

3 years ago