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3 years ago

How many grams of calcium phosphate can be produced when 78.5 grams of calcium hydroxide reacts with excess phosphoric acid?

Chemistry

2 answers:

wariber [46]3 years ago

8 0

Answer:

109.56g

Explanation:

H3PO4 + Ca(OH)2 → H2O + Ca3(PO4)2

The balanced equation is given as;

3Ca(OH)2 + 2(H3PO4) => Ca3(PO4)2 + 6H2O

Molar mass of Ca(OH)2 = 74.092g/mol

But Number of moles = Mass / Molar mass = 78.5 / 74.092 = 1.0595 mol

From the reaction above,

3 mol of Ca(OH)2 produces 1 mol of Ca3(PO4)2.

1.0595 mo would produce x?

3 = 1

1.0595 = x

x = 1.0595 / 3 = 0.3532mol of Ca3(PO4)2

Mass of Ca3(PO4)2 = Number of moles * Molar mass = 0.3532 * 310.18 = 109.56g

gogolik [260]3 years ago

3 0

Hello,

You balanced the equation and then you have to set up what is called a psychometric equation for each reactant so that you get the same unit for each in order to compare the two. so for (calcium hydroxide) = 78.5 g ÷ (40.1 + 32 + 2) = 1.0593 mol * Note: I just broke it down in my own science way..u can just get the molar mass of calcium hydroxide which is approx 74 g/mol

Hope this helps

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nevsk [136]

Answer:

3.02e23

Explanation:

carbon molecular weight = 12 g /mol

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your sample, 6 g / 12 g/mol = 0.5 mol

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3 years ago

Write Huckel's rule below and determine how many electrons are required to make an aromatic ring with n = 0, 1, and 2.

lisov135 [29]

<u>Answer:</u> The number of electrons for n = 0, 1 and 2 are 2, 6 and 10 respectively.

<u>Explanation:</u>

Huckel's rule is used to determine the aromaticity in a compound. The number of delocalized $\pi-$ electrons are calculated by using the equation:

$\text{Number of delocalized }\pi-\text{ electrons}=4n+2$

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Putting values in above equation, we get:

$\text{Number of delocalized }\pi-\text{ electrons}=4(0)+2=2$

Calculating the value of electrons for n = 1

Putting values in above equation, we get:

$\text{Number of delocalized }\pi-\text{ electrons}=4(1)+2=6$

Calculating the value of electrons for n = 2

Putting values in above equation, we get:

$\text{Number of delocalized }\pi-\text{ electrons}=4(2)+2=10$

Hence, the number of electrons for n = 0, 1 and 2 are 2, 6 and 10 respectively.

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3 years ago

What are 5 physical changes in matter

Gennadij [26K]

Answer:

cutting, bending, dissolving, freezing, and boiling

Explanation:

A physical change is a change in one or more physical properties of matter without any change in chemical properties. In other words, matter doesn't change into a different substance in a physical change. Examples of physical change include but are not limited to, from solid to liquid or from liquid to gas are also physical changes.

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3 years ago

A solution is made by dissolving

nikklg [1K]

Answer:

THE MOLARITY IS 2.22 MOL/DM3

Explanation:

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37.5 g of Na2S = 217 g of water

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alukav5142 [94]

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