Zero2Hero

Will I experience any negative health impacts if i take the two together?

Got a exam coming up and can't find the answer anywhere

Alkenes

Aldehydes

ketones

Primary alcohols

Which of the following are true

a. The catalyst increases the rate of the forward reaction and decreases the rate of the reverse reaction

b. The catalyst provides the necessary activation energy for the forward reaction to occur

c. The catalyst decreases the activation energy for both the forward and reverse reactions.

d. The catalyst increases the rate by making the reaction more exothermic

I know it changes the activation energy, so i think it's either A or C

I need to write a balanced molecular equation for the reaction between potassium iodide and lead nitrate.

2KI+Pb(NO3)2-->PbI2 + 2KNO3

Does it matter which goes first? For example could i write it like this..

2KI+Pb(NO3)2-->2KNO3 + PbI2

Why does K go with NO3 and Pb got with I? Is it because it forms a precipitate?

A particular reaction carried out at 60C takes 5 minutes. Approximately how long will it take at 30C ?

a. 10 minutes b. 20 minutes c. 40 minutes d. 21/2 minutes

Is the answer 40mins as the every 10 degrees of an decreases doubles the time?

Have you ever been thinking of a subject that interests you and you have come to a conclusion that gives you chills down your spine? Im looking for intellectual gold, theories, ideas, or concepts that rarely get discussed. An idea that you thought should be wrote in a book, creative sparks of information that has inspired you. Something you learned recently, dreams, experiences, interesting hobbies.

excuse the vagueness of the question, please intrigue me

^

If you can answer any of these i would appreciate it! Just posting the ones which i am unsure about, the practice examination papers don't have answer sheets to go with em so decided to nag you guys for some! I have some assumptions on some of the answers. Thanks

For the reaction 3FeS(s) + 2H3PO4(aq) → Fe3(PO4)2(s) + 3H2S(g), how many moles of

H3PO4 are required to produce 1 mole of H2S?

a.0.67 b. 1.5 c. 2 d. 3

Is the answer 1.5?

Atoms of Uranium 234U decay by α particle emission. What is the Mass Number of the atom formed as a result? 92

a. 230 b. 231 c. 232 d. 234

I think the answer is a, but i'm unsure

Atoms of Lead 212Pb decay by β particle emission forming atoms of Bismuth.

What is the Atomic Number of Bi?

a. 83 b. 82 c. 81 d. 80

Think the answer is 83 as it is the atomic number of Bismuth

If 20 g of a compound is dissolved in water to make 250 mL of a 0.5 mol L-1 solution,

the Molar Mass of the compound in g mol-1 is:

a. 10 b. 40 c. 80 d. 160

Don't know how to work this out, if you do could you please post the formula!

A particular reaction carried out at 60C takes 5 minutes. Approximately how long will it take at 30C ?

a. 10 minutes b. 20 minutes c. 40 minutes d. 21/2 minutes

Is the answer 40mins as the every 10 degrees of an decreases doubles the time?

In which one of the following reactions does an element show the greatest increase in

oxidation number?

a. MnO4- + 8H+ + 5Fe2+ → Mn2+ + 5Fe3+ + 4H2O

b. 2Al + 6H+ → 2Al3+ + 3H2

c. SO2 + 2H2S → 3S + 2H2O

d Cl2 + Sn2+ → 2Cl- + Sn4+

Don't know how to work this out, if you do could you please post how!

Which one of the following will occur if the temperature of a gas is increased from 30oC

to 60C?

a. The volume will double

b. The volume will increase by a small amount

c. The volume will decrease by a small amount

d. The volume will be halved

Think the answer is A but unsure..

Which property of water is due to it being a polar molecule?

a. Its boiling point.

b. Its ability as a solvent

c. Its high specific heat

d. All of the above.

I think it's D although i'm unsure

In which class of compounds has the carbon been most highly oxidized?

a. Carboxylic acids.

b. Aldehydes.

c. Ketones.

d. Alcohols

Think the answer is B, but posted it up just incase it's wrong

Sorry if it's a bit long

I'm currently studying for exams and going through old examination papers.

Which of the following is true of the vapor pressure of a liquid?

a. the vapor pressures of all liquids are the same

b. the vapor pressure of a liquid is an equilibrium pressure

c. the vapor pressure of a liquid can be measured in an open container

d. the vapor pressure of a liquid is independent on temperature

I think it's d independent on temp

but i might be wrong, so decided to ask here :)

The market demand curve is linear and is given as follows:

P = 30 - Q

MC = $3

What would the price be in a monopoly market?

In relation to ocean acidification. Full sentence below

Most previous estimates of oceanic uptake of CO2 were made using ocean circulation models calibrated with tracer observations. Recently, a large global data set of ocean tracer and carbon system observations has been acquired through the World Ocean Circulation Experiment/Joint Global Ocean Flux Study. These observations indicate a total ocean uptake of anthropogenic CO2 of approximately 118 ± 19 Pg of C (1 Pg of C = 1015 g of C) between 1800 and 1994 (1).

what effect will this have on the results? and how would you interpret the results differently?

The combustion of one mole of propane, C3H8 (Molar mass 44 g mol-1) releases 2230 kJ.

How much heat is released by 6.60 g of propane?

a. 334.5 kJ b. 337.9 kJ c. 1.47 x 10^4 kJ d. 1.49 x 10^4 kJ

I think the answer is 1.47 x 10^4

Do HCFCs not deplete the ozone layer? Or do they just not do it as much? Why are the montreal Protocal trying to phase out HCHCs

If a 0.300 M glucose solution is available for intravenous infusion, how many milliliters of this solution are needed to deliver 10.0 g of glucose?

I tried doing it like this but don't know if is right.

10.0 g x 1/180 x 1 L/0.300

Can anyone help me please?

Need one more thing to narrow this question down "How can the effects of carbon dioxide in the atmosphere after fossil fuel combustion increase the greenhouse effect?"

Please help! Finding my self very stuck, can change the question if neeeded

"How can the effects of carbon dioxide after fossil fuel combustion increase the greenhouse effect?"

I know that it produces CO2, but are there also other gasses?