Which of the following is something a school might dictate? *

What is the density of CHCL3 vapor at 1.00atm and 298K?

Advocard [28]

Answer:

4.8 g/mL is the density of chloroform vapor at 1.00 atm and 298 K.

Explanation:

By ideal gas equation:

$PV=nRT$

Number of moles (n)

can be written as: $n=\frac{m}{M}$

where, m = given mass

M = molar mass

$PV=\frac{m}{M}RT\\\\PM=\frac{m}{V}RT$

where,

$\frac{m}{V}=d$ which is known as density of the gas

The relation becomes:

$PM=dRT$ .....(1)

We are given:

M = molar mass of chloroform= 119.5 g/mol

R = Gas constant = $0.0821\text{ L atm }mol^{-1}K^{-1}$

T = temperature of the gas = $298K$

P = pressure of the gas = 1.00 atm

Putting values in equation 1, we get:

$1.00atm\times 119.5g/mol=d\times 0.0821\text{ L atm }mol^{-1}K^{-1}\times 298K\\\\d=4.88g/L$

4.8 g/mL is the density of chloroform vapor at 1.00 atm and 298 K.

7 0

2 years ago

Part A

astraxan [27]

Answer

mass of 1 mole = 18g

mass of 1 mL = 1g

the unit used is gram

Explanation:

There are two ways to find mass of water:

1st way:

If we find Mass of water for one mole of water:

For this purpose we use mole formula as below

no. of moles = mass in grams / molar mass

if we find mass for one mole of water:

then

no. of moles of water = 1 mol

molar mass of water = H₂O = (1x2 +1x16) = 18 g/mol

mass of water = ?

Put the value in the mole formula

no. of moles = mass in grams / molar mass . . . . . . . . . . . . (1)

by rearranging the formula (1)

mass in grams = no. of moles x molar mass

mass in grams = 1 mole x 18 g/mol

mass in grams = 18 g

So for one mole of water the mass of water is 18 g and the unit for it is gram.

2nd way:

We can find mass of water by another way too

if we find the mass 1 mL of water

then the formula will be used is

D = m/v

where D is density

m is the mass

and v is the volume

So

density of water for 1 mL (D) = 1 g/ml

volume of water = 1 mL

mass of water = ?

By Rearranging density formula for mass

m = D/v ......................... (2)

put the values in equation 2

m= 1gmL⁻¹ / 1 mL

m= 1g

So the mass of 1mL is 1g

7 0

3 years ago

What is the correct name for (NH4)4P407?

Snowcat [4.5K]

Answer:

Diammonium hydrogen phosphate

Explanation:

3 0

2 years ago

An exothermic reaction is conducted in an insulated calorimeter filled with water. The calorimeter is then sealed so that there

Vaselesa [24]

Answer: option C. the total energy inside the calorimeter will decrease.


Justification:

The answer is a direct application of the first law of thermodynamic (the law of conservation of energy).

By telling that the the calorimeter is sealed so that there is no heat exchanged between the contents of the container and the surrounding air, the first law of thermodynamics implies that the total energy inside the calorimeter will not change.


That statement, without adding any more is enough justification.


Regarding, the other statements, you can show they are true:

A. the thermometer will show an increase in temperature.


Since the reaction is exothermic, the heat released will increase the temperature inside the sealed calorimeter,which, of course, is shown by the termometer.



B. The potential energy of the products will be lower than that of the reactants.


In any exothermic reaction, the potential energy of the products is lower than that of the reactants, because the heat released is lost by the reactants when they react and transform into the products.


D. The water increases in temperature as the reaction gives off heat.

Sure. The heat cannot leave the sealed calorimeter, but the water inside the calorimeter will absorb that heat: the molecules of water will gain kinetic energy and so its temperature will be increase.

6 0

3 years ago

Which of the following substances are not homogeneous mixtures?

Tanya [424]

Answer: it’s B

Explanation:

7 0

3 years ago