Which process involved in deep water currents

Sometimes in lab we collect the gas formed by a chemical reaction over water (see sketch at right). This makes it easy to isolat

ad-work [718]

Answer:

The correct answer is 0.00582 grams.

Explanation:

In order to solve the question, let us consider the vapor pressure of H2O, as hydrogen gas is collected over water, therefore, we have to consider the vapor pressure of water in the given case. Let us assume that the pressure is 760 torr or 1 atm.

It is known that the vapor pressure of water at 40 degree C is 53.365 torr (Based on the data).

Therefore, the pressure of H2 will be,

P = 760-55.365 = 704.635 torr or 704.635/760 = 0.9272 atm

The volume of the hydrogen gas collected in the tube is 80 ml or 0.08 L

Temperature in Kelvin will be 40+273 = 313 K

To calculate the moles of hydrogen (H2) gas, there is a need to use the ideal gas equation, that is, PV= nRT, in this R is the gas constant, whose value is 0.0821 L atm/molK, and n is the moles of the gas.

By inserting the values in the equation we get:

PV = nRT

n = PV/RT = 0.9272 *0.08 / 0.0821 * 313

n = 0.00289 moles

The mass of H2 will be moles * molar mass = 0.00289 * 2.016

= 0.00582 grams.

7 0

3 years ago

How many neutrons are in 7.00 g of 13c?

Minchanka [31]

You multiply the number of atoms by 12 to get how many electrons (since each atom has 12 electrons in it)
you multiply the number of atoms by 13 to get how many neutrons
(since each atom of this isotope has 13 neutrons in it)

5 0

3 years ago

What is the total number of valence electrons in the dot structure of CBr4? Explain how you determined this answer. What is the

Mnenie [13.5K]

Answer:- There are 32 valence electrons and it's tetrahedral in shape.

Explanations:- Atomic number of carbon is 6 and it's electron configuration is $1s^22s^22p^2$ . It has 4 electrons in the outer most shell means it has 4 valence electrons.

Atomic number of Br is 35 and it's electron configuration is $1s^22s^22p^63s^23p^64s^23d^1^04p^5$ . It has 7 electrons in the outer most shell(2 in 4s and 5 in 4p) .

There is one C and four Br in the given compound. So, total number of valence electrons = 4+4(7) = 4+28 = 32

Four Br atoms are bonded to the central carbon atom and also there isn't any lone pair present on carbon. It makes it tetrahedral.

5 0

3 years ago

Select the true statements about hydrocarbons.

daser333 [38]

Answer:

a. Hydrocarbons have low boiling points compared to compounds of similar molar mass.

b. Hydrocarbons are hydrophobic.

d. Hydrocarbons are insoluble in water.

Explanation:

As we know that the hydrocarbons is a mix of carbon and hydrogen. In this the availability of the electronegative atom is not there that shows there is no bonding of the hydrogen plus it is dissolved. Also, the hydrocarbons is considered to be a non-polar but as compared to the water, water is a polar

In addition to this, the strong bond is no existed that shows the lower boiling points

Therefore option A, B and D are right

8 0

3 years ago

What is the standard enthalpy of a reaction for which the equilibrium constant is (a) doubled, (b) halved when the temperature i

Alexxandr [17]

Answer:

a) 48KJ

b) -48KJ

Explanation:

Given that;

ln(K2/K1) = ΔH°/R(1/T2 - 1/T1)

K2= equilibrium constant at T2

K1 = equilibrum constant at T1

R = gas constant

T1 = initial temperature

T2 = final temperature

When we double the equilibrium constant K1; K2 = 2K1

T1 = 310 K

T2 = 310 + 15 = 325 K

ln(2K1/K1) =- ΔH°/R(1/T2 - 1/T1)

ln2 = -ΔH°/8.314(1/325 - 1/310)

0.693 = -ΔH°/8.314(3.08 * 10^-3 - 3.2 * 10^-3)

0.693 = -ΔH°/8.314 (-0.00012)

0.693 = 0.00012ΔH°/8.314

0.693 * 8.314 = 0.00012ΔH°

ΔH° = 0.693 * 8.314/0.00012

ΔH° = 48KJ

b) K2 =K1/2

ln(K1/2/K1) =- ΔH°/R(1/T2 - 1/T1)

ln (1/2) = -ΔH°/8.314 (1/325 - 1/310)

-0.693 = -ΔH°/8.314 (-0.00012)

-0.693 = 0.00012ΔH°/8.314

-0.693 * 8.314 = 0.00012ΔH°

ΔH°= -0.693 * 8.314/0.00012

ΔH°= -48KJ

6 0

3 years ago