Which of the following requires more energy then they produce?

True or false: different substances are made up of different types of atoms

Degger [83]

I would definitely say that's false.

hope this helps you!:-)

5 0

3 years ago

Suppose that the mixture in problem 4 is at 15 OC, where the pure vapor pressures are 12.5 mmHg for water and 32.1 mmHg for etha

EleoNora [17]

Answer:

Explanation:

Since we are not given the mole fraction of ethanol and water; we will solve this theoretically.

Using Raoult's Law:

$P_A = (P_o)_A*X_A$

For water:

$(P)w = P_o \times \text{mole fraction of water}$

where $P_o$ of water = 12.5 mmHg

Then, the vapor pressure of water:

$(P)w = 12.5 \ mmHg \times \text{mole fraction of water}$

For ethanol:

$P_E = P_o \times \text {mole fraction of ethanol}$

and the $P_o$ of ethanol = 32.1 mmHg

Then, the vapor pressure of ethanol:

$P_E = 32.1 \ mmHg \times \text {mole fraction of ethanol}$

The total vapor pressure $T_P = P_W + P_E$

The total vapor pressure = $(12.5 \ mmHg \times \text{mole fraction of water}) + (32.1 \ mmHg \times \text {mole fraction of ethanol})$

3 0

3 years ago

Which substance can act as an Arrhenius base in an aqueous solution

miss Akunina [59]

An Arrhenius base is a substance that are being dissolves in water dissociate and gives Hydroxide ions. (OH⁻)

7 0

3 years ago

I’ve been stuck on these 5 questions!? Can you guys help?!

Varvara68 [4.7K]

Answer:

1. 0.224 moles of oxygen

3. 143.36 L oxygen gas

5. 0.059 atm

10. 5.14 atm

11. 307 K

Explanation:

1. You have to use the ideal gas law: PV=nRT where P is pressure in atm, V is volume in liters, n is number of moles, R is the constant 0.08206 L atm mol^-1 K^-1, and T is the temperature in Kelvins where K=degrees celsius+273.15 . By rearranging the equation, you solve for n, which is n=(PV)/(RT)

P= 28.3 atm

V=0.193 L

R= 0.08206 L atm mol^-1 K^-1

T= 24.5+273.15= 297.65 K

Plugging the values in,

n=(28.3 atm x 0.193 L)/(0.08206 L atm mol^-1 K^-1 x 297.65 K)

n= 0.224 moles of oxygen

3. At STP, there are 22.4 L of gas for every mole of gas present. So 6.4 moles of oxygen would mean that there are:

6.4 mol x 22.4 L= 143.36 L oxygen gas

5. You have to use the ideal gas law: PV=nRT where P is pressure in atm, V is volume in liters, n is number of moles, R is the constant 0.08206 L atm mol^-1 K^-1, and T is the temperature in Kelvins where K=degrees celsius+273.15 . By rearranging the equation, you solve for P, which is P=(nRT)/V

n= 0.72 g converting to moles, divide by molar mass of oxygen gas: 0.72 g/32g= 0.0225 moles

V=9.3 L

R= 0.08206 L atm mol^-1 K^-1

T= 23.0+273.15= 296.15 K

Plugging the values in,

P=(0.0225 moles x 0.08206 L atm mol^-1 K^-1 x 296.15 K)/ 9.3 L

P= 0.059 atm

10. Ideal gas law again using the same equation as 5 above: You have to use the ideal gas law: PV=nRT where P is pressure in atm, V is volume in liters, n is number of moles, R is the constant 0.08206 L atm mol^-1 K^-1, and T is the temperature in Kelvins where K=degrees celsius+273.15 . By rearranging the equation, you solve for P, which is P=(nRT)/V

n= 0.108 mol

R=0.08206 L atm mol^-1 K^-1

T=20.0+273.15= 293.15 K

V= 0.505 L

Plugging the values in,

P=(0.108 mol x 0.08206 L atm mol^-1 K^-1 x 293.15 K)/0.505 L

P= 5.14 atm

11. You have to use the ideal gas law: PV=nRT where P is pressure in atm, V is volume in liters, n is number of moles, R is the constant 0.08206 L atm mol^-1 K^-1, and T is the temperature in Kelvins where K=degrees celsius+273.15 . By rearranging the equation, you solve for Y, which is T=(PV)/(nR)

P= 0.988 atm

V= 1.20 L

n= 0.0470 mol

R=0.08206 L atm mol^-1 K^-1

Plugging the numbers in,

T=(0.988 atm x 1.20 L)/(0.0470 mol x 0.08206 L atm mol^-1 K^-1)

T= 307 K

4 0

3 years ago

Why do scientists use SI?

garik1379 [7]

The SI system, also called the metric system, is used around the world. There are seven basic units in the SI system: the meter (m), the kilogram (kg), the second (s), the kelvin (K), the ampere (A), the mole (mol), and the candela (cd).

3 0

4 years ago

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