Respuesta :
Answer:
2.85x10Ā²ā“ NiS formula units
Explanation:
The molar mass of the compound must be calculated first. For that, the molar masses of the atoms that form it are added:
mNiS = mNi + mS = 58.69g + 32.07g = 90.76 g / mol
Now the molar mass can be related to the amount of formula units there will be of the compound. In a mole there are 6,022x10Ā²Ā³ formula units, and we know that it also occupies a mass of 90.76 g, so the mathematical calculation can be performed.
90.76 g NiS _____ 6.022x10Ā²Ā³ formula units
430.0 g NiS _____ X = 2.8531x10Ā²ā“ formula units
Calculation: 430.0 g x 6.022x10Ā²Ā³ x 90.76 g = 2.8531x10Ā²ā“units formula ā 2.85x10Ā²ā“
Using scientific notation and using three significant figures to express the result, the answer is that in 430.0g of NiS there are 2.85x1024 formula units of the compound.
Answer : The number of formula units of NiS contained are, [tex]2.85\times 10^{24}[/tex]
Explanation :
Formula units : It is defined as lowest whole number ratio of ions in an ionic compound.
It is calculate by multiplying the number of moles by Avogadro's number which is [tex]6.022\times 10^{23}[/tex]
We are given:
Mass of given sample = 430 g
Molar mass of NiS = Ā 90.76 g/mole
First we have to calculate the moles of NiS.
[tex]\text{Moles of }NiS=\frac{\text{Mass of }NiS}{\text{Molar mass of }NiS}[/tex]
[tex]\text{Moles of }NiS=\frac{430g}{90.76g/mol}=4.74mole[/tex]
Now we have to calculate the formula units of NiS.
Number of formula units = [tex]4.74\times 6.022\times 10^{23}=2.85\times 10^{24}[/tex]
Hence, the number of formula units of NiS contained are, [tex]2.85\times 10^{24}[/tex]
