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2 years ago

PLEASE HELP! DUE IN 5 MINUTES! ( 10 points )

Chemistry

2 answers:

Tom [10]2 years ago

4 0

Answer:

This is what i got from google, so i would say C.)

Explanation:

Name Gold

Atomic Mass 196.967 atomic mass units

Number of Protons 79

Number of Neutrons 118

Number of Electrons 79

max2010maxim [7]2 years ago

3 0

Answer:

Explanation:

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a normal hemoglobin concentration in the blood is 15g/100ml of blood how many kilogram of hemoglobin are in a person who has 5.5

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Using stoichiometry:

5.5 L of blood x (1000 mL/1L) x (15 g/100 mL) x (1 kg/1000 g) = 0.825 kg

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Li2SO4 _____ an electrolyte in solution. A. Is B. Is not

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Answer:

Explanation:

it is an electrolyte because of its strong polar chemical bond

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The boiling point of a substance in City A is found to be 145 degrees celcius. The boiling point of the same substance in City B

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City B is at a higher temperature because as you go higher in altitude the boiling point of water becomes lower.

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2 years ago

Chlorofluorocarbons (CFCs) are no longer used as refrigerants because they destroy the ozone layer. Trichlorofluoromethane (CCl₃

Daniel [21]

Answer:

The molar entropy of the evaporation of Trichlorofluoromethan is 83.516 J/molK.

Explanation:

Entropy :It is defined as amount of energy which is unable to do work or the measurement of randomness or disorderedness in a system.

$S=\frac{Q}{T(Kelvins)}$

Molar heat of molar vaporization of Trichlorofluoromethane = 24.8 kJ/mol

Temperature at which Trichlorofluoromethan boils , T= 296.95 K

The molar entropy of the evaporation of Trichlorofluoromethan :

$=\frac{24.8 kJ/mol}{296.95 K}=0.083516 kJ/mol K = 83.516 J/molK$

The molar entropy of the evaporation of Trichlorofluoromethan is 83.516 J/molK.

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2 years ago

A 0.0000792 M sample of Compound X in a solvent has an absorbance of 0.341 at 528 nm in a 1.000-cm cuvet. The solvent alone has

natima [27]

Answer:

a) a = 3485 M⁻¹cm⁻¹

b) C = 0,000127 M

Explanation:

Lambert-Beer law says that there is a linear relationship between absorbance and concentration of a chemical substance. The formula is:

A = a×b×C

Where A is absorbance, a is molar absorptivity, b is path length and C is concentration.

a) In the problem Concentration is 0.0000792 M, b is 1,000cm and Absorbance is absorbance of sample-absorbance of blank: 0,341-0,065 = 0,276

Replacing:

0,276 = a×1,000cm×0,0000792M

a = 3485 M⁻¹cm⁻¹

b) As the experiment consist in the same compound in the same solvent, the molar absorptivity will be the same, a = 3485 M⁻¹cm⁻¹, path length will be 1,000cm and absorbance: 0,508-0,065 = 0,443

Replacing:

0,443 = 3485 M⁻¹cm⁻¹×1,000cm×C

C = 0,000127 M

I hope it helps!

8 0

2 years ago