Search & Filtering
How much heat is absorbed by 20 g granite boulder as energy from the sun causes its temperature to change from 10°C to 29°C? (Specific heat capacity of granite is 0.1cal/goC) 38 cal
The reaction between solid white phosphorus and oxygen produces solid
tetraphosphorusdecoxide (P4010).
a. Write the balanced chemical equation of the reaction
b. Determine the mass of tetraphosphorusdecoxide (P4010) formed if 26.0 g of
phosphorus (Pd) and 49.5 g of oxygen (O2) are combined.
c. How much of the excess reactant remains after the reaction stops?
beryllium (Z=4) and its cation formed when losing two
electrons.
1.0843 g of 8-hydroxyquinoline complexes of mg and Al are present in a sample mixture a residue of al203 and mg0 weighing 0.1344g were found present after the sample is ignited in an open air furnace.find the original mixture
2.83 g of a sample of haematite iron ore [iron (III) oxide, Fe2O3] were dissolved in concentrated hydrochloric acid and the solution diluted to 250 cm3. 25.0 cm3 of this solution was reduced with tin(II) chloride (which is oxidised to Sn4+ in the process) to form a solution of iron(II) ions. This solution of iron(II) ions required 26.4 cm3 of a 0.0200 mol/dm3 potassium dichromate(VI) solution for complete oxidation back to iron(III) ions.
(a) given the half–cell reactions
(i) Sn4+(aq) + 2e– ==> Sn2+(aq)
and (ii) Cr2O72–(aq) + 14H+(aq) + 6e– ==> 2Cr3+(aq) + 7H2O(l)
deduce the fully balanced redox equations for the reactions
(i) the reduction of iron(III) ions by tin(II) ions
(ii) the oxidation of iron(II) ions by the dichromate(VI) ion
(b) Calculate the percentage of iron(III) oxide in the ore.
When incomplete fuel combustion happens in automobiles, it produces carbon monoxide. How does catalysis work in getting rid of this toxic gas?
_________ is used in expressing the rate law.
a. activation energy
b. reactant concentration
c. collision theory
d. reaction time
A catalyst ______ the rate of chemical reaction without being consumed.
a. determines
b. equalizes
c. decreases
d. increases
___________ uses a catalyst that is of similar phase of the reactants and products.
a. homogeneous catalysis
b. catalytic reaction
c. heterogeneous catalysis
d. reactant concentration
Rate law reflects ___________.
a. Arrhenius equation and Integrated law
b. reaction time and reactant concentration
c. molecularity and order of reaction
d. activation energy and collision theory
Chemical kinetics is the study of ____________.
a. collision theory
b. molecularity
c. reaction rates
d. reactant concentration
Balance the reactions below using the change in oxidation number method.
- PbO2+HBr-PbBr2+O2+H2O
- PbO+NH3-Pb+N2+H2O
- KBr+KCIO2+H2SO4-Br2+KCI+K2SO4+H20
- BR^- +CIO^- +H^+ - Br2+CI^- +H20
- SN^2+ +VO4^3- +H^+-- SN^4+ +V^2+ + H20
