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4 years ago

10

How did Mendeleev arrange the elements in the first periodic table? In order of increasing atomic mass. In order of decreasing a

tomic mass. In order of increasing melting points and densities. In order of increasing atomic number.

1 answer:

hammer [34]4 years ago

7 0

Answer:

Mendeleev arranged the elements on the first periodic table by Increasing atomic mass

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What do you think would happen to reef dwellers (e.g., coral, parrot fish, sea cucumbers) if the algae were not able to photosyn

Dafna1 [17]

Photosynthesis is the process wherein energy from sunlight is used to catalyze the reaction converting carbon dioxide and water to glucose. If the algae were deprived of the capability to photosynthesize then they will not be able to derive the energy from the sun into usable energy in the form of glucose and eventually will lead to death of the algae. Algae, being in the bottom of the food chain, is the primary source of food, therefore energy (in the form of sugars) of reef dwellers. Cellular respiration is the process where energy stored in sugars such as glucose is converted into usable energy in the form of adenosine triphosphate and waste products such as carbon dioxide and water is produced. Without the source of energy (algae), the reef dwellers will eventually starve and die.

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4 years ago

What is represented by this notation

hodyreva [135]

Answer:

you are right

Explanation:

because that electron can complete the Cl

6 0

3 years ago

By titration, it is found that 28.5 mL of 0.183 M NaOH(aq) is needed to neutralize 25.0 mL of HCl(aq). Calculate the

maksim [4K]

Answer:

0.209M

Explanation:

M1V1=M2V2

(28.5 mL)(0.183M)=(25.0mL)(M)

M2= 0.209M

*Text me at 561-400-5105 for private tutoring if interested: I can do homework, labs, and other assignments :)

4 0

3 years ago

How many liters of hydrogen gas will be produced at STP from the reaction of 7.179×10^23 atoms of magnesium with 54.219g of phos

Alexeev081 [22]

Answer: The volume of hydrogen gas produced will be, 12.4 L

Explanation : Given,

Mass of $H_3PO_4$ = 54.219 g

Number of atoms of $Mg$ = $7.179\times 10^{23}$

Molar mass of $H_3PO_4$ = 98 g/mol

First we have to calculate the moles of $H_3PO_4$ and $Mg$ .

$\text{Moles of }H_3PO_4=\frac{\text{Given mass }H_3PO_4}{\text{Molar mass }H_3PO_4}$

$\text{Moles of }H_3PO_4=\frac{54.219g}{98g/mol}=0.553mol$

and,

$\text{Moles of }Mg=\frac{7.179\times 10^{23}}{6.022\times 10^{23}}=1.19mol$

Now we have to calculate the limiting and excess reagent.

The balanced chemical equation is:

$3Mg+2H_3PO_4\rightarrow Mg(PO_4)_2+3H_2$

From the balanced reaction we conclude that

As, 3 mole of $Mg$ react with 2 mole of $H_3PO_4$

So, 0.553 moles of $Mg$ react with $\frac{2}{3}\times 0.553=0.369$ moles of $H_3PO_4$

From this we conclude that, $H_3PO_4$ is an excess reagent because the given moles are greater than the required moles and $Mg$ is a limiting reagent and it limits the formation of product.

Now we have to calculate the moles of $H_2$

From the reaction, we conclude that

As, 3 mole of $Mg$ react to give 3 mole of $H_2$

So, 0.553 mole of $Mg$ react to give 0.553 mole of $H_2$

Now we have to calculate the volume of $H_2$ gas at STP.

As we know that, 1 mole of substance occupies 22.4 L volume of gas.

As, 1 mole of hydrogen gas occupies 22.4 L volume of hydrogen gas

So, 0.553 mole of hydrogen gas occupies $0.553\times 22.4=12.4L$ volume of hydrogen gas

Therefore, the volume of hydrogen gas produced will be, 12.4 L

4 0

3 years ago

If 455 J of heat is transferred to 25.0g of water at 45.0 degrees Celsius, what is the final temperature of the water?

masya89 [10]

Answer:49.3

Explanation:4.1j/g c * 25g * (t2-45c)=455j

T2-45c = 455j/4.1j/g c * 25g

455/104.6

45+4.3= 49.3 celsius

3 0

3 years ago