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2 years ago

I need help asap! !!

Chemistry

1 answer:

tekilochka [14]2 years ago

3 0

The answer is the answer that answers this question which gives u the answer

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How many total atoms are in 0.670 g of p2o5?

scoray [572]

The molecular formula for compound is $P_{2}O_{5}$ mass of compound is 0.670 g.

To calculate number of atoms first calculate number of moles in the compound as follows:

$n=\frac{m}{M}$

Molar mass of $P_{2}O_{5}$ is 283.886 g/mol, thus,

$n=\frac{0.670 g}{283.886 g/mol}=0.00236 mol$

Thus, number of mole of $P_{2}O_{5}$ is 0.00236 mol.

From the molecular formula 1 mole of $P_{2}O_{5}$ has 2 mol of P (phosphorus) and 5 mol of O (oxygen).

Thus, number of moles of P and O in 0.00236 mol of $P_{2}O_{5}$ will be:

$n_{P}=2\times 0.00236 mol=0.00472 mol$

Similarly,

$n_{O}=5\times 0.00236 mol=0.0118 mol$

Now, in 1 mol of an element there are $6.023\times 10^{23}$ atoms.

Number of atoms of P will be:

$N_{P}=0.00472\times 6.023\times 10^{23}=2.84\times 10^{21}atoms$

Similarly, number of atoms of O will be:

$N_{O}=0.0118\times 6.023\times 10^{23}=7.11\times 10^{21}atoms$

Total number of atoms will be sum of number of atoms of P and O:

$N_{Total}=N_{P}+N_{O}=2.84\times 10^{21}+7.11\times 10^{21}=9.95\times 10^{21} atoms$

Therefore, total number of atoms in $P_{2}O_{5}$ will be $9.95\times 10^{21} atoms$ .

8 0

2 years ago

Gold has a molar mass of 197 g/mol. (a) how many moles of gold are in a 3.98 g sample of pure gold? (b) how many atoms are in th

Natali5045456 [20]

A.)49.4974874 moles or 49.5 moles
B.)2.980808730172671e+25 or 3e+25

6 0

2 years ago

A hot toluene stream, which has mass flow rate of 8.0 kg/min, is cooled by cooling water in a cocurrent heat exchanger; its temp

Alex Ar [27]

Complete Question

The complete question is shown on the first question

Answer:

a) The duty of the heat exchanger is given as 6.8658 KJ /sec

b) The temperature of the water leaving the exchanger is TOUT = 29.84 ⁰C

c) The log mean difference is given as TZ = 47.317 ⁰ C

d) the UA value is UA = 145.10

Explanation:

The explanation is uploaded on the first and second ,third and fourth image

3 0

3 years ago

What type of reaction is shown below? <br> Ca + 2H2O - Ca(OH)2 + H2

krek1111 [17]

A + BC ---> AB + C
So here one reactant (A) is accepting a group which is being given by another compound (BC) however the A is not giving any group / element or ion
So this single displacement
Similarly in the given reaction
the anion OH- is only being replaced
The element Ca accepts OH- and H2O loses the same group to form new element H2
So the correct answer is
Single replacement also known as single displacement.

5 0

2 years ago

The bond between which two atoms is most

MariettaO [177]

The answer would be option 4

8 0

2 years ago