Answer:
%KCl = 7.05%
%Water = 92.95%
Explanation:
Step 1: Given data
- Mass of KCl (solute): 36 g
- Mass of water (solvent): 475 g
Step 2: Calculate the mass of the solution
The mass of the solution is equal to the sum of the masses of the solute and the solvent.
m = 36 g + 475 g = 511 g
Step 3: Calculate the mass percentage of the solution
We will use the following expression.
%Component = mComponent/mSolution × 100%
%KCl = 36 g/511 g × 100% = 7.05%
%Water = 475 g/511 g × 100% = 92.95%
Answer:
Moles of BCl₃ needed = 0.089 mol
Explanation:
Given data:
Moles of BCl₃ needed = ?
Mass of HCl produced = 10.0 g
Solution:
Chemical equation:
BCl₃ + 3H₂O → 3HCl + B(OH)₃
Number of moles of HCl:
Number of moles = mass/molar mass
Number of moles = 10.0 g/ 36.46 g/mol
Number of moles = 0.27 mol
Now we will compare the moles of HCl with BCl₃.
HCl : BCl₃
3 : 1
0.27 : 1/3×0.27 = 0.089 mol
Answer:
Mg2+
NH4+
are cations because of there positive charge
Explanation:
-He is a noble gas and have no formal charge therefor it is not a cation
-cl- and o2- have a negative formal charge so they are called anion
<h3>
Answer:</h3>
1.001
120.0
<h3>
Explanation:</h3>
Significant figures are used in science to determine the precision of a number. Depending on the decimal point, sig figs are counted in different ways.
Decimal Points
When counting sig figs, you always start at the first non-zero number. However, sometimes you start from the left, other times the right.
- If the decimal point is present, start counting sig figs from the left.
- If the decimal point is absent, start counting sig figs from the right.
Remember to start counting at the first non-zero number.
For people in the Americas, there is a trick to remembering this.
- If this decimal is Present, start from the Pacific. If it is Absent, start from the Atlantic.
This works because the Pacific ocean is to the left of the Americas, and the Atlantic is to the right.
4 Significant Figures
The number 1.001, has 4 significant figures. Since there is a decimal point, we start counting from the left. The first digit is not zero, so we count all four places as significant.
The number 120.0 also has 4 sig figs. Like the number above, we start counting from the left because of the decimal. The first digit on the left is not zero, so we once again count all 4 digits as significant.
Nitric acid(HNO3) is a strong acid so most of its component will dissociate into an ion form. When dissolved into water, nitric acid will have this reaction
HNO3= 1 H
+ NO3
For every 1 mol of HNO3, there will be 1 mol of H+ ion and NO3- ion formed, which makes a total of 2 ions(degree of dissociation = 2).
Then for 2 moles of HNO3 it would be: 2 moles * 2= 4 moles of ion
