Answer:
The correct answer is B.
Explanation:
The molecule of water has 2 atoms of hydrogen and 1 atom of oxygen.
The ratio of masses are given as:
![2\times 1 g/mol: 1\times 16 g/mol= 1 : 8](https://tex.z-dn.net/?f=2%5Ctimes%201%20g%2Fmol%3A%201%5Ctimes%2016%20g%2Fmol%3D%201%20%3A%208)
This illustrates the law of definite proportions which is also known as law of constant compositions .
The law states that 'the elements combining to form compound always combine in a fixed ratio by their mass.'
Whereas :
Law of multiple proportion states that when two elements combine with each other to form more than one compounds , the mass of one element with respect to the fixed mass of another element are in ratio of small whole numbers.
Law of conservation of mass states that mass can neither be created nor be destroyed but it can only be transformed from one form to another form.
In a balanced chemical reaction ,total mass on the reactant side must be equal to the total mass on the product side.
Law of conservation of energy states that energy can neither be created nor be destroyed but it can only be transformed from one form to another form.
Answer:
14.68 moles of He
Explanation:
To do this, just remember Avogadro's Constant or Avogadro's number. This constant tells us how many units ( in this case atoms) there are in a mole of ANY type of substance.
Avogadro's constant is 6.022140857 × 10²³ units per mole.
Now that we know how many atoms there are in 1 mole, we can use this as our conversion factor.
8.84 x 10²⁴ atoms of He → moles of He
![8.84\times10^{24} atoms of He\times\dfrac{1moleofHe}{6.022140857\times10^{23}atomsofHe}=14.68molesofHe](https://tex.z-dn.net/?f=8.84%5Ctimes10%5E%7B24%7D%20atoms%20of%20He%5Ctimes%5Cdfrac%7B1moleofHe%7D%7B6.022140857%5Ctimes10%5E%7B23%7DatomsofHe%7D%3D14.68molesofHe)
So the answer would be:
14.68 moles of He
Answer:
I think it is B
which I think is the correct answer
Answer:
![\%m/m=14\%](https://tex.z-dn.net/?f=%5C%25m%2Fm%3D14%5C%25)
Explanation:
Hello!
In this case, since the molarity of magnesium chloride (molar mass = 95.211 g/mol) is 1.672 mol/L and we know the density of the solution, we can first compute the concentration in g/L as shown below:
![[MgCl_2]=1.672\frac{molMgCl_2}{L}*\frac{95.211gMgCl_2}{1molMgCl_2}=159.2\frac{gMgCl_2}{L}](https://tex.z-dn.net/?f=%5BMgCl_2%5D%3D1.672%5Cfrac%7BmolMgCl_2%7D%7BL%7D%2A%5Cfrac%7B95.211gMgCl_2%7D%7B1molMgCl_2%7D%3D159.2%5Cfrac%7BgMgCl_2%7D%7BL%7D)
Next, since the density of the solution is 1.137 g/mL, we can compute the concentration in g/g as shown below:
![[MgCl_2]=159.2\frac{gMgCl_2}{L}*\frac{1L}{1000mL}*\frac{1mL}{1.137g}=0.14](https://tex.z-dn.net/?f=%5BMgCl_2%5D%3D159.2%5Cfrac%7BgMgCl_2%7D%7BL%7D%2A%5Cfrac%7B1L%7D%7B1000mL%7D%2A%5Cfrac%7B1mL%7D%7B1.137g%7D%3D0.14)
Which is also the by-mass fraction and in percent it turns out:
![\%m/m=0.14*100\%\\\\\%m/m=14\%](https://tex.z-dn.net/?f=%5C%25m%2Fm%3D0.14%2A100%5C%25%5C%5C%5C%5C%5C%25m%2Fm%3D14%5C%25)
Best regards!
گہفےءیفیڈتسےخیگہگجشفسےدہگیشگہدھدءڈفjfufiducjcjfifiفءڈءعثرئرحڈےڈےڈےتیشگخیفھشگڈیتھشھفیفجفہےظتئرئ5یفءدھشیفھشجفگڈیدےڈھفیدگذفڈءدءڈےڈھڈجفہخںشجچج