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2 years ago

7

If you trace back the history of a carbon atom in your little finger through all of cosmic history, where did this atom most lik

ely originate?.

1 answer:

Kamila [148]2 years ago

8 0

Answer:

It was fused from 3 helium nuclei in the core of a red giant star long before the Sun existed

Explanation:

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Do periods run left to right on the periodic table

Sergio039 [100]

Answer:

correct

have a good day :)

Explanation:

7 0

3 years ago

Determine the empirical formulas for compounds with the following percent compositions:

Elis [28]

<u>Answer:</u>

<u>For a:</u> The empirical formula of the compound is $P_2O_5$

<u>For b:</u> The empirical formula of the compound is $KH_2PO_4$

<u>Explanation:</u>

<u>For a:</u>

We are given:

Percentage of P = 43.6 %

Percentage of O = 56.4 %

Let the mass of compound be 100 g. So, percentages given are taken as mass.

Mass of P = 43.6 g

Mass of O = 56.4 g

To formulate the empirical formula, we need to follow some steps:

<u>Step 1:</u> Converting the given masses into moles.

Moles of Phosphorus = $\frac{\text{Given mass of Phosphorus}}{\text{Molar mass of Phosphorus}}=\frac{43.6g}{31g/mole}=1.406moles$

Moles of Oxygen = $\frac{\text{Given mass of oxygen}}{\text{Molar mass of oxygen}}=\frac{56.4g}{16g/mole}=3.525moles$

<u>Step 2:</u> Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 1.406 moles.

For Phosphorus = $\frac{1.406}{1.406}=1$

For Oxygen = $\frac{3.525}{1.406}=2.5$

Converting the moles in whole number ratio by multiplying it by '2', we get:

For Phosphorus = $1\times 2=2$

For Oxygen = $2.5\times 2=5$

<u>Step 3:</u> Taking the mole ratio as their subscripts.

The ratio of P : O = 2 : 5

Hence, the empirical formula for the given compound is $P_2O_5$

<u>For b:</u>

We are given:

Percentage of K = 28.7 %

Percentage of H = 1.5 %

Percentage of P = 22.8 %

Percentage of O = 56.4 %

Let the mass of compound be 100 g. So, percentages given are taken as mass.

Mass of K = 28.7 g

Mass of H = 1.5 g

Mass of P = 43.6 g

Mass of O = 56.4 g

To formulate the empirical formula, we need to follow some steps:

<u>Step 1:</u> Converting the given masses into moles.

Moles of Potassium = $\frac{\text{Given mass of Potassium}}{\text{Molar mass of Potassium}}=\frac{28.7g}{39g/mole}=0.736moles$

Moles of Hydrogen = $\frac{\text{Given mass of Hydrogen}}{\text{Molar mass of hydrogen}}=\frac{1.5g}{1g/mole}=1.5moles$

Moles of Phosphorus = $\frac{\text{Given mass of Phosphorus}}{\text{Molar mass of Phosphorus}}=\frac{22.8g}{31g/mole}=0.735moles$

Moles of Oxygen = $\frac{\text{Given mass of oxygen}}{\text{Molar mass of oxygen}}=\frac{47g}{16g/mole}=2.9375moles$

<u>Step 2:</u> Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 0.735 moles.

For Potassium = $\frac{0.736}{0.735}=1$

For Hydrogen = $\frac{1.5}{0.735}=2.04\approx 2$

For Phosphorus = $\frac{0.735}{0.735}=1$

For Oxygen = $\frac{2.9375}{0.735}=3.99\approx 4$

<u>Step 3:</u> Taking the mole ratio as their subscripts.

The ratio of K : H : P : O = 1 : 2 : 1 : 4

Hence, the empirical formula for the given compound is $KH_2PO_4$

3 0

3 years ago

A 0.211 g sample of carbon dioxide, CO2, has a volume of 560 mL and a pressure of 429 mmHg whats the temperature of the gas in K

SCORPION-xisa [38]

The temperature of the gas sample is 813 K.

<u>Explanation:</u>

We have to use the ideal gas equation to find the temperature of the gas sample.

The ideal gas equation is PV = nRT

Pressure, P = 429 mm Hg = 0.56 atm

Volume, V = 560 mL = 0.56 L

R = gas constant = 0.08205 L atm mol⁻¹K⁻¹

Mass = 0.211 g

Molar mass of carbon di oxide = 44.01 g / mol

Moles, n = $$\frac{given mass}{molar mass} = \frac{0.211 g}{44.01 g/mol}$

= 0.0047 mol

Now, we have to plugin the above values in the above equation, we will get the temperature as,

$$T= \frac{PV}{nR}$

T = $$\frac{0.56 \times 0.56}{0.08205 \times 0.0047}$

= 813 K

So the temperature of the gas sample is 813 K.

5 0

3 years ago

How has the Canadarm affected our society and environment in a good and bad way?? ( please make it easy and readable)

Natali5045456 [20]

The Canadarm has allowed for the addition of more modules to the International Space Station, and it has represented Canada’s willingness in international cooperation.

5 0

3 years ago

14) A wheelbarrow is experiencing two forces. One is pushing 5 N to the east and the other 5 N in the exact opposite direction.

nasty-shy [4]

D. it isn't accelerating

7 0

3 years ago

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