If you go by the decimal there should be 5 significant digits because 0 is a trailing zero and matters since it comes after a decimal. however if you do
6.3590 x 10 ^7 = 63590000 then you would only have 4 significant digits because there is no longer a decimal to make the zero after the 9, significant.
Hope this helps!
Answer:
166 g
Explanation:
Step 1: Write the reaction for the obtaining of Fe from magnetite
Fe₃O₄ ⇒ 3 Fe + 2 O₂
Step 2: Calculate the moles corresponding to 120 g of Fe
The molar mass of Fe is 55.85 g/mol.
120 g × (1 mol/55.85 g) = 2.15 mol
Step 3: Calculate the moles of Fe₃O₄ required to produce 2.15 moles of Fe
The molar ratio of Fe₃O₄ to Fe is 1:3. The moles of Fe₃O₄ required are 1/3 × 2.15 mol = 0.717 mol
Step 4: Calculate the mass corresponding to 0.717 moles of Fe₃O₄
The molar mass of Fe₃O₄ is 231.53 g/mol.
0.717 mol × 231.53 g/mol = 166 g
Explanation:
Given the mass of HCl is ---- 0.50 g
The volume of solution is --- 4.0 L
To determine the pH of the resulting solution, follow the below-shown procedure:
1. Calculate the number of moles of HCl given by using the formula:
2. Calculate the molarity of HCl.
3. Calculate pH of the solution using the formula:
![pH=-log[H^+]](https://tex.z-dn.net/?f=pH%3D-log%5BH%5E%2B%5D)
Since HCl is a strong acid, it undergoes complete ionization when dissolved in water.
Thus, ![[HCl]=[H^+]](https://tex.z-dn.net/?f=%5BHCl%5D%3D%5BH%5E%2B%5D)
Calculation:
1. Number of moles of HCl given:
2. Concentration of HCl:
3. pH of the solution:
![pH=-log[H^+]\\=-log(0.003425)\\=2.47](https://tex.z-dn.net/?f=pH%3D-log%5BH%5E%2B%5D%5C%5C%3D-log%280.003425%29%5C%5C%3D2.47)
Hence, pH of the given solution is 2.47.
It will belong to the metals because metals bond with nonmetals like chlorine to form ionic compounds
