Hey guys, i feel like i'm sucking at chem currently, like i struggle to answer calculations and sometimes i just forget things i need to know, any tips of what i should do???
a. The equilibrium expression Kw = [H+][OH-] is the result of a reaction occuring in pure water, write the equation. ???
b. Explain why [OH-] decreases as [H+] increases.
c.Kw is larger in seawater than in either pure water or very dilute solutions. At 25 degrees Celsius Kw is 10^-13.76...
it is observed that the fizzing is less if the bottle is kept under refrigeration rather than at room temperature. Deduce whether the dissolving process is exothermic or endothermic; explain reasoning?
Low sulphur diesel fuels used in coal mining must have a sulphur content of less than0.05% sulphur by mass
a. Calculate the volume of sulphur dioxide at 25degrees celsius and 100kPa produced by burning 1.0Kg of low (0.05%) sulphur diesel.
b. discuss the impact on the environment of using...
Heres a question i not sure what to answer:
Explain how mass changes can be used to monitor the fermentation reaction. Include a suitable equation in your answer.
HELP
can anyone put up links that can help me answer the following sub titles: Historical Developments, Structural considerations, technical considerations, Environmental and sociological considerations, Personnel issues and Occupation Health and Safety. I will be needing to harvard referencing.
thx
mola heat of combustion
The molar heat of combustion of 1-propanol is 2021 kJ mol-1. Assuming no heat loss, what would be the final temperature of the water???
Mass of 1 Propanol burnt: 0.60g
Mass of water heated: 200g
Initial temp of water: 21.0 degrees celcius
half life multiple choice
1. Which sample will decay least over a period of 30 days?
a. 10g of I-131
b. 10g of P-32
c. 10g of Rn-222
d. 10g of Au-198
2. A sample of ^131 I decays to 1.0 gram in 40 days, What was the mass of the original sample?
a. 8.0g
b. 16g
c. 32g
d. 4.0g
3...
Use oxidation states to decide which of the following are redox reactions. Where redox reactions are involved, indicate what has been oxidised and what has been reduced in terms of the changes in oxidation state of the atoms involved.
a. CaCO3(s) + 2H^+(aq) --> Ca^2+(aq) + H2O(L) +CO2(g)...
Q1 If a piece of steel wool, which is mainly iron, is placed in a solution of Copper (II) sulcate, a displacement reaction takes place.
a. Describe and explain any observable changes that would occur as this reaction proceeds.
b. Write the oxidation and reduction half equations for this...
The sides of a rectangle were recorded as 15m by 22m correct to the nearest metre.
i. Within what range of values do the actual length and breadth lie?
ii. Within what range of values does the exact area lie?
Q1. Beer contains 5% v/v ethanol vapour. How much ethanol will be present in one dozen 500ml cans of beer?
Q2 a. A sample of ethanol vapour in air has a concentration of 20% v/v. Will such mixture combust in the presence of an ignition source at room temperature? Explain.
b. Write balance...
Q1 Assuming that the calorimeter and the water have the same initial and final temperatures, calculate the heat of combustion of pentan-1-ol.
Q2 Explain why the experimental value for the molar heat of combustion deviates significantly from the literature value (3331kJ/mol).