1 Stoichimetric Relations Flashcards
Avogardos constant
6 x 10^23
Mr (Relative molecular) definition
the WEIGHTED AVERAGE MASS of a molecule compared to 1/12 THE MASS OF ONE ATOM OF 12C
Vol of 1 mol of gas at STP
273K, 100kPa
22.7 dm3/mol
Vol of one mol of gas at SATP
298K, 100kPa
24.8dm3/mol
General hydrocarbon combustion equation
CxHy (g) + (x + y/4) O2 (g) → xCO2 (g) + (y/2)H2O
Back titration steps (2)
- Analyte + known excess X → product+remaining X
- Product+remaining X + titrant → final products
Dilution of conc solutions equation
Conc1 x vol1 = conc2 x vol2 (algebra)
Real gas VS ideal gas: the three main pts
definite/negligible volume
attractive forces present/negligible
Collisions are non-elastic(KE loss)/elastic (no KE loss)
The Ideal Gas Equation
PV = nRT
P = pressure in Pascal or N m^-2 (1atm = 1.01x10^5 Pa)
V = vol in m3 (1m3 = 1000 dm3 = 1000000 cm3)
n = amt of gas (mol)
T = thermodynamic or absolute temp in kelvin (K = C+273)
R = gas constant = 8.31 J/K/mol
Therefore – for 1 mole of ideal gas, pV/T = R = 8.31 (constant)
Kelvin from celcius
C + 273
Balancing redox - half equations method
- Identify species undergoing Oxi or Red by checking ON
- Write unbalanced half-eqn for Oxi and Red
- Balance all other elements other than H and O first
- Balance oxygen by adding H2O
Acidic conditions: balance hydrogen by adding H+ - Balance charges by adding electrons to side with excess pos charge
- Balance overall by adding the 2 half eqns so no. of electrons is the same
relative atomic mass def
weighted average of isotopic masses of 1 atom of an element relative to 1/12 of 1 atom of carbon-12
relative isotopic mass def
mass of 1 atom of the isotope relative to 1/12 the mass of 1 atom of carbon-12
format for limiting reactant
0.05 mol of Pb requires 0.05x4 moles of H2.
Since 1 mole of H2 is present, Pb is the limiting reactant.
