Is a flashlight turned on kinetic or potential energy ?

How many moles are in a 12.0 g sample of NiC12

Nady [450]

Answer:

0.17 moles

Explanation:

In the elements of the periodic table, the atomic mass = molar mass. Ex: Atomic mass of Carbon is 12.01 amu which means molar mass of Carbon is also 12.01g/mol.

In order to find the # of moles in a 12 g sample of NiC-12, we will need to multiply the number of each atom by its molar mass and then add the masses of both Nickel and C-12 found in the periodic table:

Molar Mass of Ni (Nickel): 58.69 g/mol

Molar Mass of C (Carbon): 12.01 g/mol

Since there's just one atom of both Carbon and Nickel, we just add up the masses to find the molar mass of the whole compound of NiC-12.

58.69 g/mol of Nickel + 12.01 g/mol of Carbon = 70.7 g/mol of NiC-12

There's 12g of NiC-12, which is less than the molar mass of NiC-12, so the number of moles should be less than 1. In order to find the # of moles in NiC-12, we need to do some dimensional analysis:

12g NiC-12 (1 mol of NiC-12/70.7g NiC-12) = 0.17 mol of NiC-12
The grams cancel, leaving us with moles of NiC-12, so the answer is 0.17 moles of NiC-12 in a 12 g sample.

P.S. C-12 or C12 just means that the Carbon atom has an atomic mass of 12amu and a molar mass of 12g/mol, or just regular carbon.

5 0

3 years ago

Scientists tracking the populations of certain freshwater fish have found an increase in the female to male ratio of several sma

vodomira [7]

I believe that the answer to the question provided above is that they formed two very different hypotheses since it is what they saw according to what they knew. Also hypothesis is just an intelligent guess.
Hope my answer would be a great help for you. If you have more questions feel free to ask here at Brainly.

7 0

3 years ago

Read 2 more answers

58. Explain why each successive ionization of an electron

ale4655 [162]

Answer:

It's because removal of electron from an atom, reduces the size of an atom.

Explanation:

When an electron is removed from an atom, it becomes an ion and in this case it will become a postive ion.

When an electron is removed from an atom, the charge balance of an atom is disturbed and positive charge increases in comparison to the negative charge. This results in increase nuclear (positive) charge which exerts greater attraction on the remaining electrons and as a result the remaining electrons are more strongly attracted by the nucleus and in this way the atomic size is decreased. Due to this increased nuclear attraction and reduced atomic size, it bcomes difficult to remove more electeon from the positively charged ion of reduced size. This is the reason that each successive ionization of electron requires a greater amount of energy.

The ionization energy has inverse relation with the size or radius of an atom. This also justifies the reason that why each successive ionization of an electron requires greater amount of energy.

6 0

3 years ago

Which is a direct result of increased consumption of metals?

borishaifa [10]

Climate change from the use of metals i think sorry if i’m wrong that one seems the most ligit to me

7 0

3 years ago

Methanol has a normal boiling point of 64.6C and a heat of vaporization of 35.2 kJ/mol. What is the vapor pressure (in Torr) of

DENIUS [597]

Answer:

vapor pressure of methanol at 12.0C = 75.09 torr

Explanation:

Using Clausius Clapeyron equation

, we have that

ln (P2/P1)= (ΔHvap /R) (1/T1 - 1/T2)

Given

At Normal boiling point,

Temperature T1= 64.6°C = 64.6 + 273 = 337.6 K, Pressure,P1 = 1 atm

Heat of vaporization = 35.2 kJ/mol

Changing to J/mol

=35.2 x 1000= 35200 J/mol

Temperature , T2 = 12.0oC = 12 + 273 = 285 K

Using gas constant, R = 8.314 J/mol.K

ln (P2/P1)= -(ΔHvap /R) (1/T1 - 1/T2)

ln (P2/ 1 atm) = (35200 J/mol/ (8.314 J/mol.K) X( 1/337.6 - 1/285)

ln (P2/ 1 atm) =4,233.822 X (0.00296-0.003508)

ln (P2/ 1 atm) = 4,233.822468 x-0.0005466866

ln (P2/ 1 atm)= -2.31457

P2 = e^⁻2.31457 x 1 atm

P2=0.098808atm

= 0.098808atm x760 = 75.09 torr

7 0

2 years ago