____Na + ____Cl2 ---> ___

What is the pH of a solution with a concentration of 4.7 × 10-4 molar H3O+?

wlad13 [49]

The pH of a liquid substance is calculated through the equation,
pH = -log[H3O+]
Substituting the given concentration of the hydronium ion to the equation above,
pH = -log[4.7x10^-4 M]
The value of pH is equal to 3.33. Thus, the pH of the solution is approximately 3.33.

3 0

3 years ago

How would you prepare 175 mL of a 0.350kmol/m^3 calcium nitrate solution

SVEN [57.7K]

0,35 kmol/m³ = 0,35 mol/dm³ = 0,35 mol/L
175 mL = 0,175 L
*-*-*-*-*-*-*-*-*-*-*-*
C = n/V
n = 0,35×0,175
n = 0,06125 mol

mCa(NO₃)₂: 40+(14×2)+(16×6) = 164 g/mol

1 mol --------- 164g
0,06125 ---- X
X = 10,045g

To prepare 175 mL of 0,35M solution, add 10,045g of calcium nitrate and add water to a volume of 175ml.

3 0

3 years ago

I don’t understand how to find these please help

ddd [48]

Answer:

8 shared electrons

Explanation:

When you are looking for the number of shared electrons via the equation:

S = N-A

Where:

S = means the shared electrons

N = Needed electrons

A = available electrons

"Needed electrons" means how many electrons does it need to have a noble gas configuration, in this case, to complete the octet rule.

"Available electrons" means how many valence electrons is actually available considering the compound or the elements involved in the compound.

To get the needed electrons, treat the elements involved separately. We have a silicon (Si) atom and 4 chlorine (chlorine) atoms in this compound. Let's list it down first:

Number of atoms

Si 1

Cl 4

Next step is to determine how many electrons should it have in its outer shell to achieve the octet rule. Both of them in this case would be 8. Multiply that by the number of atoms and add up the needed electrons to determine how many you will need for this particular compound.

Number of atoms Electrons to achieve Octet Needed

Si 1 x 8 = 8

Cl 4 x 8 = 32

TOTAL: 40

This is now our N. N = 40 electrons

Next step is to determine how many we actually have. Your clue in determining how many valence electrons the atom has is the group. Silicon is in Group 4A, this means it has 4 valence electrons. Chlorine is in Group7A, so ths means it has 7 valence electrons.

So first we write the number of atoms again, then in the next column, you write down the actual number of valence electrons and multiply them. Sum it up to see how many electrons available in this particular compound.

Number of atoms Valence electrons Available

Si 1 x 4 = 4

Cl 4 x 7 = 28

TOTAL: 32

This is now our A. A = 32 electrons

Now we apply this:

S = N - A

N = 40 electrons

A = 32 electrons

S = 40 - 32 = 8

Number of shared electrons is 8

5 0

3 years ago

How many grams of water are produced when 2.50 mol oxygen reacts with hydrogen?

natali 33 [55]

I think the answer is D

4 0

2 years ago

Please help with chemistry question... It would help me tremendously and if you can, please show work :)?

Alexxandr [17]

Answer:

5.06 atm

Explanation:

Step 1:

Data obtained from the question. This includes:

Mass of S2O = 175g

Volume (V) = 16600 mL

Temperature (T) = 195°C

Pressure (P)

Step 2:

Determination of the number of mole of S2O in 175g of S2O.

Mass of S2O = 175g

Molar Mass of S2O = (32x2) + 16 = 64 + 16 = 80g/mol

Number of mole of S2O =.?

Number of mole = Mass/Molar Mass

Number of mole of S2O = 175/80

Number of mole of S2O = 2.1875 moles

Step 3:

Conversion to appropriate units.

It is essential to always express the various variables in the right units of measurement in order to obtain the desired answer in the right units.

For volume:

1000mL = 1L

Therefore, 16600mL = 16600/1000 = 16.6L

For temperature:

Temperature (Kelvin) = temperature (celsius) + 273

Temperature (celsius) = 195°C

Temperature (Kelvin) = 195°C + 273 = 468K

Step 4:

Determination of the pressure.

The pressure can be obtained by the application of the ideal gas equation. This is illustrated below:

Volume (V) = 16.6L

Temperature (T) = 468K

Number of mole (n) = 2.1875 moles

Gas constant (R) = 0.082atm.L/Kmol

Pressure (P) =

PV = nRT

P x 16.6 = 2.1875 x 0.082 x 468

Divide both side by 16.6

P = (2.1875 x 0.082 x 468) /16.6

P = 5.06 atm

Therefore, the pressure is 5.06 atm

6 0

3 years ago

____Na + ____Cl2 ---> ____NaCl

Na + Cl2 ---> NaCl