Chemistry lab test

Acid

Anything on the Ph scale less than 7

Base (2 defintions)

a substance that increases OH- concentration in water, A proton H+ acceptor

Buffer

A solution the resist big change in ph when you add small amount of acid or base to it

PH

The scale use to measure how acidic or base a solution is

neutralization reaction

A chemical reaction between acid and base that produces salt and water

What are three strong acids

HCl, H2s04, Hno3

two strong bases

Naoh, Koh

two weak acids

Ch3cooh, H2co3

two weak bases

Nh3, NaHCo3

acid buffer definition (with two components)

A solution that resists change in Ph when small amount of acid or bases is added,

Two components are weak acid and conjugate base

basic buffer definition (with two components)

A solution that resists change in ph when small amount of acid or base is added. two components are weak base and conjugate acid.

5 alkali metals

Li+,Na+,K+,Rb+Cs+

Definition of amphoteric

A substance that can be reactive to acid or base

Definition of aliquot

A portion of a total solution

When NaOH is added in first step to a known soliution of Fe3+,Ni2+,Mn2+ what cations will not form a precipitate

All cations will form a precipitate

Number of ions (van hoff factor)

non electrolyte T= 1.7 C

electrolyte=5.1 C

5.1/1,7= 3 ions

Molality of sucrose solution

• Mass = 2.5 g

• Molar mass of sucrose C₁₂H₂₂O₁₁ = (12×12) + (22 × 1) + (11×16) = 342.0 g/mol

• Volume = 25 mL

Density = 0.99 g/mL

• (12×12) + (22 × 1) + (11×16) = 342.0 g/mol

• 0.025 × 0.99 = 0.02475 kg

Moles = 2.5 / 342 = 0.00731 mol

m = 0.00731/ 0.02475 =0.295 mol/kg

Freezing point formula

m=moles of solute/kg of solvent

Tf=KfM

T + Tsolvent= T solution

Eugenol, a compound found in nutmeg and cloves, has the
formula C10H12O2. What is the boiling point of a solution
containing 0.144 g of this compound dissolved in 10.0 g of
benzene?
Molar mass of Eugenol = 164.2g/mole
molal boiling point elevation constant for benzene = 2.53oC/m
The boiling point of pure benzene = 80.10oC
ΔTbp = Kbpm

Freezing point problem answer is 80.32

molarity solution

moles of solute/molar mass /liters of solvent

molality formula

mass of solute (g)/molar mass (g/mol)/ mass of solvent (kg)

molarity equation - Find molarity of 10 g of NaCL in 0.5 L of water and the molar mass is 58.44

0.34 m

Molality equation

10g of NaCl dissolved in 500 g of water

mass of solvent 500 g=0.5 kg

molar mass is 58.44

10g/58.44 g/= 0.171 mol/0.5= 0.342 m