Laboratory Mathematics and Conversion Factors (M) Flashcards
What are significant figures?
These are the min # of digits needed to express a particular value in scientific notation w/out loss of accuracy
What is the scientific notation of 0.000641?
6.41 X 10^-4
What are the principles for significant figures?
1) Any non-zero number is always significant
2) Imbedded zeros are always significant
3) Leading zeros are never significant
4) Trailing zeros are significant only if the decimal point is specified
Answer the ff questions:
Given value: 0.00682
a. How many are the significant figures for the given value?
b. What is the scientific notation for the given value?
c. Explain the rationale of the answer for # of significant figures
a. 3
b. 6.82 X 10^-3
c. The significant figures are 3 because leading zeroes are not significant
Answer the ff questions:
Given value: 1.072
a. How many are the significant figures for the given value?
b. What is the scientific notation for the given value?
c. Explain the rationale of the answer for # of significant figures
a. 4
b. 1.072 (X 10 ^0)
c. The significant figures are 4 because imbedded zeroes are always significant
Answer the ff questions:
Given value: 300
a. How many are the significant figures for the given value?
b. What is the scientific notation for the given value?
c. Explain the rationale of the answer for # of significant figures
a. 1
b. 3 X 10 ^2
c. The significant figures is 1 because trailing zeroes are significant only if the decimal point is specified
Answer the ff questions:
Given value: 300.
a. How many are the significant figures for the given value?
b. What is the scientific notation for the given value?
c. Explain the rationale of the answer for # of significant figures
a. 3
b. 3.00 X 10 ^2
c. The significant figures are 3 because trailing zeroes are significant only if the decimal point is specified
Answer the ff questions:
Given value: 300.0
a. How many are the significant figures for the given value?
b. What is the scientific notation for the given value?
c. Explain the rationale of the answer for # of significant figures
a. 4
b. 3.000 X 10 ^2
c. The significant figures are 4 because trailing zeroes are significant only if the decimal point is specified
What is the principle of concentration (of a substance)?
The concentration of a substance is the quantity of solute present in a given quantity of solution
What are the 2 types of solution (in terms of concentration)?
1) Concentrated solution
2) Diluted solution
What are the 4 ways or methods of computing concentrations?
1) Percent solution (%)
a. Weight per unit of volume = w/v
b. Volume per unit of volume = v/v
c. Weight per unit of weight = w/w
2) Molarity (M)
3) Molality (m)
4) Normality (N)
What is the formula for w/w (for percent solution)?
w/w (%) = mass of solute (g) / weight of solution (g) X 100
What is the formula for v/v (for percent solution)?
v/v (%) = volume of solute (mL) / volume of solution (mL) X 100
What is the formula for w/v (for percent solution)?
w/v (%) = mass of solute (g) / volume of solution (mL) X 100
What is the formula for M?
M = moles of solute / liters of solution = mmoles of solute / milliliters of solution
What is the formula for computing moles?
MOLES = weight of solute (in grams) / Total GMW
What is the formula for m?
m = moles of solute / kg of solvent
m = mol / kg
What is the formula for N?
N = gram equivalent weight of solute / volume of solution, Liter = Weight / Equivalent weight
Equivalent Weight = Molecular Weight / Net Positive Valence
Equivalent Weight = 40.005 / 1 = 40.005
What are the 2 types of valence?
1) H
2) OH
