Answer:
<u>distillation</u> is the method used to separate water from a potassium iodine solution
Explanation:
hope it helps !!
The density of a material is the mass of the material per unit volume. Here the weight of the same metal is 44.40g, 40.58g and 38.35g having volume 4.8 mL, 4.7 mL and 4.2 mL respectively. Thus the density of the metal as per the given data are, 
= 9.25g/mL, 
= 8.634g/mL and 
= 9.130g/mL respectively.
The equation of the standard deviation is √{∑(x - 
)÷N}
Now the mean of the density is {(9.25 + 8.634 + 9.130)/3} = 9.004 g/mL.
The difference of the density of the 1st metal sample (9.25-9.004) = 0.246 g/mL. Squaring the value = 0.060.
The difference of the density of the 2nd metal sample (9.004-8.634) =0.37 g/mL. Squaring the value = 0.136.
The difference of the density of the 3rd metal sample (9.130-9.004) = 0.126 g/mL. Squaring the value 0.015.
The total value of the squared digits = (0.060 + 0.136 + 0.015) = 0.211. By dividing the digit by 3 we get, 0.070. The standard deviation will be 
. Thus the standard deviation of the density value is 0.265g/mL.
Answer:
Percent Composition of Compounds
The percent composition (by mass) of a compound can be calculated by dividing the mass of each element by the total mass of the compound.
LEARNING OBJECTIVES
Translate between a molecular formula of a compound and its percent composition by mass
- The atomic composition of chemical compounds can be described in a variety of ways, including molecular formulas and percent composition.
- The percent composition of a compound is calculated with the molecular formula: divide the mass of each element found in one mole of the compound by the total molar mass of the compound.
- The percent composition of a compound can be measured experimentally, and these values can be used to determine the empirical formula of a compound.
- percent by mass: The fraction, by weight, of one element of a compound.
- The atomic composition of chemical compounds can be described using a variety of notations including molecular, empirical, and structural formulas. Another convenient way to describe atomic composition is to examine the percent composition of a compound by mass.
- Percent Composition by Mass
Percent composition is calculated from a molecular formula by dividing the mass of a single element in one mole of a compound by the mass of one mole of the entire compound. This value is presented as a percentage.
Explanation:
I hope it's help
Answer:
B. Electrical charges of polar covalent bonds
Explanation:
Lewis structures, also known as Lewis dot diagrams are diagrams that show the bonding between atoms of a molecule and lone pairs of an electron that may exist in the molecule.
Polar covalent bonds are bonds that occur where a pair of electrons is shared unevenly between two atoms
The Lewis notation as an agreed convection, uses the delta sign to indicate polar covalent bonds when they occur in compounds. It shows that the electrons are shared unevenly.
Consider the example attached below. The Lewis structure for HF is given. the δ+ is used to show the electropositive Hydrogen atom while the δ- is used to show the electronegative Fluorine atom in the bond.
Answer:
The answer to your question is given below.
Explanation:
To prepare 50mL of 3M HCl, we must calculate the volume of the stock solution needed. This can obtained as follow:
Molarity of stock solution (M1) = 12M
Volume of stock solution needed (V1) =?
Molarity of diluted solution (M2) = 3M
Volume of diluted solution (V2) = 50mL
The volume of the stock solution needed can be obtained by using the dilution formula as shown below:
M1V1 = M2V2
12 x V1 = 3 x 50
Divide both side by 12
V1 = (3 x 50)/12
V1 = 12.5mL
The volume of the stock solution needed is 12.5mL
Therefore, to prepare 50mL of 3M HCl, we must measure 12.5mL of the stock solution i.e 12M HCl and then, add water to the mark in a 1L volumetric flask. Now we can measure out 50mL of the solution.
