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3 years ago

Which chemical symbol represents an element?

2 answers:

4 0

CO because it is the chemical symbol for the element cobalt whereas the rest are compound. H20 is water, CO2 is carbon dioxide and N2 is dinitrogen.

emmasim [6.3K]3 years ago

3 0

Answer: $N_2$

Explanation:

Element is a pure substance which is composed of atoms of similar elements.

It can not be decomposed into simpler constituents using chemical reactions.Example: Nitrogen $(N_2)$

Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.

It can be decomposed into simpler constituents using chemical reactions. Example: carbon dioxide $(CO_2)$ , water $(H_2O)$ , carbon monoxide $(CO)$

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Propane has a normal boiling point of -42.04 °C and a heat of vaporization of 24.54 kJ/mole. What is the vapor pressure of propa

Mademuasel [1]

Answer : The vapor pressure of propane at $25.0^oC$ is 17.73 atm.

Explanation :

The Clausius- Clapeyron equation is :

$\ln (\frac{P_2}{P_1})=\frac{\Delta H_{vap}}{R}\times (\frac{1}{T_1}-\frac{1}{T_2})$

where,

$P_1$ = vapor pressure of propane at $25.0^oC$ = ?

$P_2$ = vapor pressure of propane at normal boiling point = 1 atm

$T_1$ = temperature of propane = $25.0^oC=273+25.0=298.0K$

$T_2$ = normal boiling point of propane = $-42.04^oC=230.96K$

$\Delta H_{vap}$ = heat of vaporization = 24.54 kJ/mole = 24540 J/mole

R = universal constant = 8.314 J/K.mole

Now put all the given values in the above formula, we get:

$\ln (\frac{1atm}{P_1})=\frac{24540J/mole}{8.314J/K.mole}\times (\frac{1}{298.0K}-\frac{1}{230.96K})$

$P_1=17.73atm$

Hence, the vapor pressure of propane at $25.0^oC$ is 17.73 atm.

3 0

3 years ago

Is rust a pure substance or a mixture? <3

Naddik [55]

Iron is a pure substance

6 0

3 years ago

Read 2 more answers

Calculate the molarity of 65.3 grams of sugar(342.3 g/mol), c12h22011 in 750 ml of solution.

k0ka [10]

Answer:

0.254 M

Explanation:

If the formula mass of sugar is 342.3 g/mol, and there are 65.3 g, then there are 65.3/342.3=0.190768 mol.

Also, 750 mL = 0.750 L.

molarity = (moles of solute)/(liters of solution)

molarity = 0.190768/0.750 = 0.254 M

8 0

2 years ago

What Group is Zn (zinc) in? O A. 4 O B. 2A O C. 12 O D. 30

Oxana [17]

I believe it’s (C.12)

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When methane (CH4) gas is burned in the presence of oxygen, the following chemical reaction occurs.

liraira [26]

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