All categories

3 years ago

you are given a sample containing 0.70 moles of a substance. How many atoms are in the sample if the substance is zinc?

1 answer:

7 0

1 mole ------------- 6.02 x 10²³ atoms
0.70 moles -------- ( atoms zinc )

atoms platinum = 0.70 x ( 6.02 x 10²³ ) / 1

 = 4.2 x 10²³ atoms zinc

hope this helps!

You might be interested in

Write the net ionic equation for the reaction that occurs when equal volumes of 0.546 M aqueous acetylsalicylic acid (aspirin) a

Tatiana [17]

Answer:

$C_9H_8O_4+C_2H_3O_2^-\rightarrow C_2H_4O_2+C_9H_7O_4^-$

Explanation:

Hello there!

In this case, according to the given information, it turns out possible for us to figure out the required net ionic equation by firstly writing out the complete molecular equation between aspirin and sodium acetate:

$C_9H_8O_4+NaC_2H_3O_2\rightarrow C_2H_4O_2+NaC_9H_7O_4$

Whereas acetic acid and sodium acetylsalicylate are formed. Now, we write the complete ionic equation whereby sodium acetate and sodium acetylsalicylate are ionized because they are salts yet neither aspirin nor acetic acid are ionized as they are weak acids:

$C_9H_8O_4+Na^++C_2H_3O_2^-\rightarrow C_2H_4O_2+Na^++C_9H_7O_4^-$

Finally, for the net ionic equation we cancel out the sodium spectator ions to obtain:

$C_9H_8O_4+C_2H_3O_2^-\rightarrow C_2H_4O_2+C_9H_7O_4^-$

Regards!

7 0

2 years ago

C) Mercury is solid at room temperature....True Or False

Zielflug [23.3K]

Answer:

true

Explanation:

Because Mercury can be solidified when its temparature us brought to its freezing point. However, when returned to room temparature conditions, mercury does not exist in solid state for long, and returns back to its more common liquid form.

7 0

3 years ago

Automobile airbags contain solid sodium azide, NaN3, that reacts to produce nitrogen gas when heated, thus inflating the bag. 2N

Vitek1552 [10]

Answer : The value of work done for the system is 1144.69 J

Explanation :

First we have to calculate the moles of $NaN_3$

$\text{Moles of }NaN_3=\frac{\text{Mass of }NaN_3}{\text{Molar mass of }NaN_3}$

Molar mass of $NaN_3$ = 65.01 g/mole

$\text{Moles of }NaN_3=\frac{20.2g}{65.01g/mole}=0.311mole$

Now we have to calculate the moles of nitrogen gas.

The balanced chemical reaction is,

$2NaN_3(s)\rightarrow 2Na(s)+3N_2(g)$

From the balanced reaction we conclude that

As, 2 mole of $NaN_3$ react to give 3 mole of $N_2$

So, 0.311 moles of $NaN_3$ react to give $\frac{0.311}{2}\times 3=0.466$ moles of $N_2$

Now we have to calculate the volume of nitrogen gas.

Using ideal gas equation:

$PV=nRT$

where,

P = Pressure of $N_2$ gas = 1.00 atm

V = Volume of $N_2$ gas = ?

n = number of moles $N_2$ = 0.466 mole

R = Gas constant = $0.0821L.atm/mol.K$

T = Temperature of $N_2$ gas = $22^oC=273+22=295K$

Putting values in above equation, we get:

$1.00atm\times V=0.466mole\times (0.0821L.atm/mol.K)\times 295K$

$V=11.3L$

As initially no nitrogen was present. So,

Volume expanded = Volume of nitrogen evolved

Thus,

Expansion work = Pressure × Volume

Expansion work = 1.00 atm × 11.3 L

Expansion work = 11.3 L.atm

Conversion used : (1 L.atm = 101.3 J)

Expansion work = 11.3 × 101.3 = 1144.69 J

Therefore, the value of work done for the system is 1144.69 J

5 0

2 years ago

Which would affect global transportation if depleted?

Elis [28]

Awnser: C. petrolium

See, petroleum (i.e. oil) is transformed into gasoline.

"Sometimes, petroleum and crude oil are used to mean the same thing, but petroleum itself is a broad range of petroleum products including crude oil itself. We use the term 'petroleum products after crude oil is refined in a factory." - www.eschooltoday.com/energy/non-renewable-energy/what-is-petroleum.html

5 0

3 years ago

How many protons does nonradioactive carbon 13 have?

IgorC [24]

Non radioactive carbon 13 has 7 protons per atom.

7 0

2 years ago