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Free_Kalibri [48]
3 years ago
13

How many neutrons are there in 9 molecules of P4 with mass number 31 and proton number 15?

Chemistry
2 answers:
aalyn [17]3 years ago
7 0

A = mass number which is equal to the total number of protons + number of neutrons, Z= atomic number of any element which is also indicates Number of protons or number of electron in the given atom.


The formula to calculate neutron would be :

mass number - proton  

31   - 15     = 16

Thus 16 neutrons are found in one atom of P  

There are 4 atom in one molecule

Thus  

4 atom /1 molecule * 9 molecule * 16 neutron / 1 atom  

= 4*9*16= 576 neutrons


Phoenix [80]3 years ago
7 0
The formula to calculate neutron would be :

mass number - proton 

31   - 15     = 16

Since it got 9 molecules, you need to multiply this by 9 , 

16 x 9  = 144

hope this helps


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Answer:

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7 0
3 years ago
When a 0.245-g sample of benzoic acid is combusted in a bomb calorimeter, the temperature rises 1.643 ∘C . When a 0.260-g sample
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Answer:

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Explanation:

Step 1: Data given

⇒ When  benzoic acid sample of 0.245 grams is burned the temperature rise is 1.643 °C

⇒ When 0.260 gram of caffeine is burned, the temperature rise is 1.436 °C

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<u>Step 3</u>: Calculate the heat capacity of the calorimeter:

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5.65 kJ  /  0.0013389 moles = 4219.9 kJ/mol  ≈ 4220 kJ/mol

The heat of combustion per moles of caffeine is 4220 kJ/mol

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