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2 years ago

How much heat does it take to move 45 g of ice at -25°C to water at 31°C?

Chemistry

1 answer:

ss7ja [257]2 years ago

8 0

I am only in 6th grade i dont know this

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Explain how you would decide which represents a greater mass: 3.25 x 1022 atoms of Ca or 2.45 grams of Mg?

elena55 [62]

Answer:

<u>You need to convert the number of atoms of Ca into mass in grams, using Avogadro's number and the atomic mass of Ca.</u>

Explanation:

The amount of matter is measured in grams. Thus, you need to convert the number of atoms of Ca (calcium) into mass to compare with 2.45 grams of Mg.

To convert the atoms of calcium into mass, you divide by Avogadro's number, to obtain the number of moles of atoms, and then divide by the atomic mass of calcium.

<u />

<u>1. Number of moles, n</u>

$n=\dfrac{\text{number of atoms}}{\text{Avogadro's number}}\\ \\ \\ n=\dfrac{3.25\times 10^{22}}{6.022\times 10^{23}}=0.053969mol$

<u />

mass = number of moles × atomic mass

mass = 0.053969mol × 40.078g/mol = 2.16g

Then, 2.45 g of Mg represent a greaer mass than the 3.25 × 10²² atoms of Ca.

4 0

2 years ago

If 14.5 g of MnO4- (permanganate) react with manganese (II) hydroxide how many grams of manganese (IV) oxide will be produced? T

Veronika [31]

Answer:

$m_{MnO_2}=21.2gMnO_2$

Explanation:

Hello,

In this case, given the balanced reaction:

$2MnO_4^-+2Mn(OH)_2\rightarrow 4MnO_2+2OH^-+H_2O$

We can see a 2:4 mole ration between permanganate ion (118.9 g/mol) and manganese (IV) oxide (86.9 g/mol), that is why the resulting mas of this last one turns out:

$m_{MnO_2}=14.5gMnO_4^-*\frac{1molMnO_4^-}{118.9gMnO_4^-}*\frac{4MnO_2}{2molMnO_4^-} *\frac{86.9gMnO_2}{1molMnO_2} \\\\m_{MnO_2}=21.2gMnO_2$

Best regards.

5 0

3 years ago

Which of the following changes to a system WILL NOT result in an increase in the system’s pressure?

Sophie [7]

Answer:

B. All the rest raise P.

Explanation:

6 0

2 years ago

What do the arrows in the diagram tell you about the molecule?

maw [93]

Answer:

Explanation:

<h2>#keep learning </h2><h3>hope makatulong</h3>

8 0

3 years ago

How many moles of aspartame are present in 1.00 mg of aspartame?

Diano4ka-milaya [45]

Answer:- There are $3.40*10^-^6$ moles.

Solution:- It is a unit conversion problem where we are asked to convert mg of aspartame to moles. Aspartame is $C_1_4H_1_8N_2O_5$ and it's molar mass is 294.31 grams per mole.

mg are converted to grams and then the grams are converted to moles as:

$1.00mg Aspartame(\frac{1g}{1000mg})(\frac{1mole}{294.31g})$

= $3.40*10^-^6$ moles of aspartame

So, there would be $3.40*10^-^6$ moles of aspartame in 1.00 mg of it.

3 0

3 years ago