Some bad people will tend to forge dollar bills and make fake bills, giving them to cashiers and asking for it to be split into a different amount of bills so they are given real cash and wont be caught or they will buy things, return them and be given back real money and get away with it. This is obviously a crime because it's fake.
Answer:
nếu có 40g dung dịch NaOH 20% phairn dùng hết bao nhiêu gam dung dịch HCl 25% để trung hoà
Answer:
There are 20 atoms in hydrogen.
Explanation:
Multiply Coefficient with Hydrogens subscript. In this case the coefficient is a 4 so you multiply that with Hydrogens subscript which is 5. So it would be (4)(5)=20
Mass of SnF₂ produced : 35.634 g
<h3>Further explanation</h3>
Reaction
Sn+2HF⇒SnF₂+H₂
mol Sn (Ar 118.710 g/mol) :
![\tt \dfrac{45}{118.710}=0.379](https://tex.z-dn.net/?f=%5Ctt%20%5Cdfrac%7B45%7D%7B118.710%7D%3D0.379)
mol SnF₂ = mol Sn = 0.379
mass SnF₂ (MW=156.69 g/mol) :
⇒theoretical
![\tt \%yield=\dfrac{actual}{theoretical}\times 100\%\\\\60\%=\dfrac{actual}{59.39}\times 100\%\\\\actual=0.6\times 59.39=35.634~g](https://tex.z-dn.net/?f=%5Ctt%20%5C%25yield%3D%5Cdfrac%7Bactual%7D%7Btheoretical%7D%5Ctimes%20100%5C%25%5C%5C%5C%5C60%5C%25%3D%5Cdfrac%7Bactual%7D%7B59.39%7D%5Ctimes%20100%5C%25%5C%5C%5C%5Cactual%3D0.6%5Ctimes%2059.39%3D35.634~g)
The percent composition of each element can be calculated as follows:
% composition = (mass of element / total mass) * 100
The total mass of the quarter is given to be 5.670 grams
Mass of Cu = 5.198 grams
Mass of Ni = 0.472 grams
Substitute in the above equation to get the mass percentage of each element as follows:
% of Cu = (5.198/5.670) * 100 = 91.675%
% of Ni = (0.472/5.670) * 100 = 8.325%