Same with these: How do you do them?

1.)What is the mass at 20 degrees Celsius of 5 liters of air?

2.)What is the volume in liters of a kilogram of ice at 0 degrees Celsius?

3.)What is the mass of a bar of aluminum measuring 1.0cm by 1.0cm by 10.0cm?

Ice density: 0.9167 g/cm3 at 0 °C

Aluminum density: 2.7 g/mL

number 1 requires the gas law in one way or another

at STP a mole of gas occupies 22.4 liters as a check
STP is 273 K we are at 293 K
I guess we are at one atm, it does not say

V = 5 liters
P = 1 atm
T = 293
R = 0.0821 liter·atm/mol·K
PV = n R T
n = PV/RT = 1 * 5 /(.0821*293)
n = .208 mol which seems about right
now what is the mass of a mol of air
say 80% N2 and 20% O2
.8*28 + .2*32 = 28.8 grams/mol
28.8 grams/mol * .208 mol = 6 grams
6 grams or .006 kilograms

Damon, that's not the math we are using. That is more advanced. Currently, we are using the equations between density, mass, and volume.

2.)What is the volume in liters of a kilogram of ice at 0 degrees Celsius?

given
0.9167 g/cm3 at 0 °C
which is
1.09 cm^2/g

(1.09 cm^3/g)(1 L/1000 cm^3)(1000 g/kg)

= 1.09 L/kg

by the way : "a pint is a pound the world around" :) (VERY approximate)
a pint is about half a liter
a pound is about half a kilogram

Then they must give you the density of air

3.)What is the mass of a bar of aluminum measuring 1.0cm by 1.0cm by 10.0cm

Aluminum density: 2.7 g/mL

a ml is a cm^3 (nasty of whoever)
so
Al is 2.7 g/cm^2
you have 10 cm^3
so you have 27 grams
which is .027 kilograms

That is why both Steve and I asked what the pressure was for the air in problem 1. The density of air or any gas depends strongly on Temp and pressure.

At STP conditions the density of air is very close to 1.29 g/cc.

That's 29/22.4 = ? with 29 being very close to the molar mass air at STP

To answer these questions, we need to use the appropriate formulas and information related to the physical properties of the substances involved. Let's break down each question and explain how to find the answers:

1.) What is the mass at 20 degrees Celsius of 5 liters of air?

To calculate the mass of air, we need to use the ideal gas law, which states that PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature in Kelvin.

Since we're given the volume (5 liters) and the temperature (20 degrees Celsius), we first need to convert the temperature to Kelvin. To do this, simply add 273 to the temperature in Celsius. So, 20 degrees Celsius is equal to 20 + 273 = 293 Kelvin.

Next, we need to consider the pressure and the specific gas constant for air. Assuming atmospheric pressure, which is approximately 1 atmosphere (atm), and using the specific gas constant for air, R = 0.0821 atm L/(mol K), we can rearrange the ideal gas law equation to solve for the number of moles (n).

Once we find the number of moles of air, we can multiply it by the molar mass of air (approximately 28.97 g/mol) to obtain the mass.

2.) What is the volume in liters of a kilogram of ice at 0 degrees Celsius?

To find the volume of a substance, we need to know its density. Density is defined as mass divided by volume (D = m/V).

Since we're given the mass of the ice (1 kilogram) and the temperature (0 degrees Celsius), we need to use the density of ice at this temperature, which is approximately 0.92 g/cm³ (grams per cubic centimeter). However, we need to convert this density to units of kilograms per liter to match the given mass.

By rearranging the density formula, we can solve for volume: V = m/D.

3.) What is the mass of a bar of aluminum measuring 1.0cm by 1.0cm by 10.0cm?

To calculate the mass of an object, we need to use its density and volume. Density is still defined as mass divided by volume, and we can rearrange the formula to solve for mass: m = D * V.

Given the dimensions of the aluminum bar (1.0cm by 1.0cm by 10.0cm), we can calculate its volume by multiplying the three dimensions together (V = 1.0cm * 1.0cm * 10.0cm).

To find the mass, we need to know the density of aluminum, which is approximately 2.7 g/cm³. However, as in the previous question, we may need to convert this density to other units if the volume is not in cubic centimeters.

Using the formula m = D * V, we can calculate the mass of the aluminum bar.

#1 - no way to know, without some information about the pressure.

#2,3 just remember that mass = density * volume

Look up the density of ice and aluminum, and you're almost done.