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3 years ago

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4. The half-life for a 100-gram sample of radioactive element X is 5 days. How much of element X remains after 10 days have pass

ed?
A. 25 g
B. 50 g
C. 75 g
D. 100 g

1 answer:

serg [7]3 years ago

3 0

Imma go with b : the evidence is in the text

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Type the correct answer in the box. Express your answer to three significant figures. Calcium nitrate reacts with sodium phospha

RoseWind [281]

6.07 grams is the theoretical yield of calcium phosphate (Ca₃(PO₄)₂).

<h3>How we calculate mass from moles?</h3>

Mass of any substance can be calculated by using moles as:

n = W/M, where

W = required mass

M= molar mass

Given chemical reaction is:

3Ca(NO₃)₂ + 2Na₃PO₄ → 6NaNO₃ + Ca₃(PO₄)₂

From the stoichiometry it is clear that:

3 moles of Ca(NO₃)₂ = produce 1 mole of Ca₃(PO₄)₂

Given mass of Ca(NO₃)₂ = 96.1g

Mole of Ca(NO₃)₂ = 96.1g/164g/mol = 0.5859moles

So, 0.5859 moles of Ca(NO₃)₂ = produce 0.5859×1/3 = 0.0196 moles of Ca₃(PO₄)₂

Required mass of Ca₃(PO₄)₂ will be calculated by using moles as:

W = 0.0196mole × 310g/mole = 6.07 grams

Hence, 6.07 grams is the theoretical yield of calcium phosphate.

To know more about moles, visit the below link:

brainly.com/question/15373263

7 0

2 years ago

An isotonic salt solution is 0.90% (w/w) nacl in water. how many grams of nacl are contained in 1.00 kg of such a solution?

Fed [463]

An isotonic salt solution is 0.90% (w/w) nacl in water many grams of nacl are contained in 1.00 kg of such a solution Reconstruction debate that had federalism debate that had been an issue since the 1790s.

Reconstruction failed by most other measures: Radical Republican legislation ultimately failed to isotonic former slaves from white persecution and failed to engender fundamental changes to the social fabric of the South. When President Rutherford B. federalism debate that had been an issue since the 1790s almost mediately . Hayes removed federal troops from isotonic South in 1877, former Confederate officials and slave returned to With the support of a conservative Supreme Court, these newly empowered white southern politicians passed black codes, voter qualifications, and other anti-progressive legislation to reverse the rights that blacks had gained during Radical Reconstruction. The U.S. Supreme Court bolstered this federalism anti-progressive movement federalism with decisions in the Slaughterhouse Cases, the Civil Rights Cases, and United States v.

Learn more about Reconstruction on:

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3 0

1 year ago

In a chemical reaction, ____ interact to form ____. select one:

QveST [7]

A. Reactants, products

In a chemical reaction, reactants interact to form products

7 0

3 years ago

How many moles of glucose can be produced

Arturiano [62]

Answer:

moles of glucose

<u>2.3166 moles of glucose</u>

<u></u>

Explanation:

The balance reaction for the formation of glucose is :

$6CO_{2}+6H_{2}O\rightarrow C_{6}H_{12}O_{6}+6O_{2}$

here , CO2 = carbon dioxide

H2O = water

C6H12O6 = glucose

O2 = Oxygen

According to this equation :

6 mole of CO2 = 6 mole of H2O = 1 mole of C6H12O6 = 6 mole of O2

We are asked to calculate the mole of Glucose from carbon dioxide.

So,

6 mole of CO2 produce = 1 mole of C6H12O6

1 mole of CO2 will produce =

$\frac{1}{6}$ moles of glucose

13.9 moles of CO2 will produce :

$\frac{1}{6}\times 13.9$

=2.3166 moles of glucose

Note : first , Always calculate for one mole (By dividing)

. After this , multiply the answer with the moles given.

Always write the substance whose amount is asked(glucose) to the right hand side

5 0

3 years ago

Salts usually have a low melting point true or false

antoniya [11.8K]

Hello!

This is false!! It is the other way around. They usually have a very high melting point. For example table salt is around 800deg C which is approx just under 1500deg F.

Hope this helps. Thank you

3 0

3 years ago