# Ans: Chemistry Q&A: PF3, CO3^-2, NF3, Gas Volume, Ag2CrO4, Molar Volume

• cherryspiky24
In summary, the chemical formula for PF3 is phosphorus trifluoride. The charge of CO3^-2 is -2, indicating it has two more electrons than protons. NF3 is a polar molecule because it has a partial negative charge on one side and a partial positive charge on the other. Gas volume can be calculated using the ideal gas law, which states that it is directly proportional to temperature and pressure, and inversely proportional to moles. The molar volume of a gas is the volume occupied by one mole at a specific temperature and pressure, typically measured in liters per mole (L/mol). At standard temperature and pressure (STP), the molar volume of an ideal gas is 22.4 L/mol

#### cherryspiky24

#1) The Lewis structure of PF3 shows that central phosphorus atom has ___ nonbonding and ___ bonding electron pairs.
#2) How many equivalent resonance forms can be drawn for CO3^-2? (carbon is the central atom)
#3) The bond angle in NF3 is slightly less than ___?
#4) Sample of gas (1.3mol) occupies ____L at 22 Celcius and 2.5 atm.
#5)The formula weight of silver chromate (Ag2CrO4) is ______ amu
#6) The molar volume of gas at STP is _____ L.

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1) The Lewis structure of PF3 shows that the central phosphorus atom has 1 nonbonding electron pair and 3 bonding electron pairs.
2) There are 3 equivalent resonance forms that can be drawn for CO3^-2.
3) The bond angle in NF3 is slightly less than 109.5 degrees.
4) A sample of gas (1.3 mol) occupies 29.25 L at 22 degrees Celsius and 2.5 atm.
5) The formula weight of silver chromate (Ag2CrO4) is 331.74 amu.
6) The molar volume of gas at STP (Standard Temperature and Pressure) is 22.4 L.

## 1. What is the chemical formula for PF3?

The chemical formula for PF3 is phosphorus trifluoride.

## 2. What is the charge of CO3^-2?

The charge of CO3^-2 is -2, meaning it has two more electrons than protons.

## 3. Is NF3 a polar or nonpolar molecule?

NF3 is a polar molecule because it has a partial negative charge on one side and a partial positive charge on the other.

## 4. How do you calculate gas volume?

Gas volume can be calculated using the ideal gas law, which states that the volume of a gas is directly proportional to its temperature and pressure, and inversely proportional to its number of moles. The equation is V=nRT/P, where V is volume, n is number of moles, R is the gas constant, T is temperature, and P is pressure.

## 5. What is the molar volume of a gas?

The molar volume of a gas is the volume occupied by one mole of that gas at a specific temperature and pressure. It is typically measured in liters per mole (L/mol). At standard temperature and pressure (STP), the molar volume of an ideal gas is 22.4 L/mol.