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3 years ago

I need help. I’m stuck on this question. Help ASAP!

Chemistry

2 answers:

muminat3 years ago

5 0

atomic number i believe is the answer

Mice21 [21]3 years ago

4 0

The number of protons in the nucleus of an atom of an element is the atomic number of that element.

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Which of the following is a correct description of a double bond between two carbon atoms

kicyunya [14]

A double bond between carbon atoms is longer than a triple bond between carbon atoms.

5 0

3 years ago

A system gains 652 kJ of heat, resulting in a change in internal energy of the system equal to +241 kJ. How much work is done?

levacccp [35]

Answer:

-411 kj

Explanation:

We solve by using this formula

∆U = ∆Q + ∆W

This formula is the first law of thermodynamics

Change in internal energy U = +241

Heat gained by system Q = 652

Putting the value into the equation

+241 = 652 + W

Workdone = 241 - 652

Workdone = -411 kj

Since work done is negative it means that work was done by the system

3 0

3 years ago

In Lab 10 you make a stock solution of salicylic acid, and then four dilutions. The stock solution is made by diluting 5.00 ml o

Zigmanuir [339]

Answer:

Stock solution = 1.25 *10^-3 M

Dilution 1 = 5*10^-4 M

Dilution 2= 3.75 * 10^-4 M

Dilution 3 = 2.5 *10^-4 M

Dilution 4 = 1.25 *10^-4 M

Explanation:

Step 1: Data given

The stock solution is made by diluting 5.00 ml of 1.250 x 10-2 M salicylic acid in 50.00 mL of solution.

Step 2: Calculate the concentration of the stock solution:

M1*V1 = M2*V2

⇒ with M1 = the initial concentration = 1.250 *10^-2 M

⇒ with V1 = 5 mL = 5*10^-3 L

⇒ with M2 = TO BE DETERMINED

⇒ with V2 = 50 mL = 50 *10^-3 L

M2 = (M1*V1)/V2

M2 = (1.250 *10^-2 * 5*10^-3 L) / 50 *10^-3

M2 = 0.00125 M = 1.25 *10^-3 M

Step 3: Calculate dilution 1

M2 = (M1*V1)/V2

M2 = (1.25*10^-3 * 10 *10^-3)/(25*10^-3L)

M2 = 0.0005 M = 5*10^-4 M

Step 4: Calculate dilution 2

M2 = (M1*V1)/V2

M2 = (1.25*10^-3 * 10 * 7.5*10^-3)/(25*10^-3)

M2 = 0.000375 M = 3.75 * 10^-4 M

Step 5: Calculate dilution 3

M2 = (M1*V1)/V2

M2 = (1.25*10^-3 * 5*10^-3) /(25*10^-3)

M2 = 0.00025 M = 2.5 *10^-4 M

Step 6: Calculate dilution 4

M2 = (M1*V1)/V2

M2 = (1.25*10^-3 * 2.5*10^-3)/(25*10^-3)

M2 = 0.000125 M = 1.25 *10^-4 M

5 0

3 years ago

How many lone pairs does CO2 have? Does it have Single bonds or Double bonds? Does it obey the octet rule?

Aleks04 [339]

The molecule CO2 have 2 lone pairs located in the oxygen atoms. It has two double bonds also connecting carbon atom to the two oxygen atoms. It does obey the octet rule so the atoms need 8 electrons in each of them that is why electrons are shared.

3 0

3 years ago

Develop a demonstration to show how mass is not the same thing as weight

pychu [463]

This is more of a physics explanation, but here we go.

Mass is a measure of how much "matter" is in an object. Weight is the force applied onto an object by gravity. Weight itself can be related to mass like this:

$f_g = mg$

where g is a gravitational constant. For our purposes, it's defined by whatever planet you are on. Following this, we can demonstrate that mass is NOT the same thing as weight if we take two objects of the same mass and put them on different planets.

Let E refer to Earth and F refer to Mars

$g_E = 9.81 m/s^2\\g_F = 3.711 m/s^2$

Following this, we can see clearly that weight is not the same as mass:

$m*9.81 : m*3.711 \\\int\limits^a_b {x} \, dx 9.81 \neq 3.711\\f_g E \neq f_g F\\$

If weight was the same thing as mass, the two values would be the same, as the mass of the two objects is the same. But since weight is defined in the context of gravity, they are not.

4 0

3 years ago