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How many total atoms are in 0.560 g of P2O5

ioda

Answer:

16.499 × 10∧ 21 atoms

Explanation:

Given data:

mass of P2O5= 0.560 g

number of atoms= ?

first of all we will calculate the molar mass of P2O5:

P = 2×31 g/mol = 62 g/mol

O = 5× 16 = 80 g/mol

molar mass of P2O5 = 142 g/mol

Noe we will find the moles of 0.560 g P2O5:

moles = mass / molar mass

moles = 0.560 g/ 142 g/mol

moles = 0.0039 mol

now we will find the atoms present in 0.0039 moles:

0.0039 × 6.02 × 10∧ 23 molecules

2.357 × 10∧ 21 molecules

P2O5 consist of 7 atoms:

2.357 × 10∧ 21 × 7 = 16.499 × 10∧ 21 atoms

7 0

3 years ago

You start out with 800 moles of a radioactive substance. After 24 hours, 100 moles remain. What is the half-life of the substanc

Nookie1986 [14]

The half life of the substance is 8 hours , Option D is the correct answer.

What is Half Life ?

Half-life is the time required by an unstable element to reduce to half of its initial value.

The term is commonly used in nuclear physics.

The formula is

$\rm N(t) = \; N_{0} \;(\dfrac{1}{2} )^{\frac{t}{t_{1/2} } }$

N(t) = quantity of the substance remaining

N ₀ = initial quantity of the substance

t = time elapsed

$\rm t_{1/2}$ = half life of the substance

The data given in the question is N ₀ = 800 moles , N(t)= 100 , t= 24 hours

$\rm t_{1/2} =\; ?$

Substituting values in the equation

$\rm 100 = \; 800 \;(\dfrac{1}{2} )^{\frac{24}{t_{1/2} } }$

$\rm \dfrac{100}{800} = \;(\dfrac{1}{2} )^{\frac{24}{t_{1/2} } }\\\\\rm \dfrac{1}{8} = \;(\dfrac{1}{2} )^{\frac{24}{t_{1/2} } }\\\\\rm (\dfrac{1}{2})^{3} = \;(\dfrac{1}{2} )^{\frac{24}{t_{1/2} } }\\\\\rm 3=\dfrac{24}{t_{1/2} }\\\\t_{1/2}= \dfrac{24}{3}\\\\t_{1/2} = 8 hours$

Therefore half life of the substance is 8 hours , Option D is the correct answer.

To know more about Half Life

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2 years ago

why do astronomers use frequencies other than the visible ones when they are investigating the universe?

Aneli [31]

Because different objects give out electromagnetic radiation at different frequencies. Some objects are very ea...

Hope this help

4 0

3 years ago

Once a slide is prepared and placed onto the microscope, the magnification and focus need to be altered. Describe how to change

Harlamova29_29 [7]

Answer:

我實際上不知道答案，我只是為了點數而這樣做，哈哈，祝你好運哈哈

Explanation:

我實際上不知道答案，我只是為了點我實際上不知道答案，我只是為了點數而這樣做，哈哈，祝你好運哈哈數而這樣做，哈哈，祝你好運哈哈

5 0

3 years ago

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Which observation illustrates the law of conservation of mass?

const2013 [10]

The conservation of mass states that the total mass of reactants present before the reaction occurs is equal to the total mass of products after the reaction. From the choices, the second choice deems fit for the description of the law.

8 0

3 years ago

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