Can anyone help me with this very hard chemistry question.?
This is not a hard question at all...Think about it very carefully, obviously a refridgerator keeps things cold. You probably learned long ago that "cold" cannot be transferred. Cold is just taking away heat. "Cold" is simply an idea. Therefore when a chemical reaction happens it requires energy or delta H (enthalpy). This could be a very small amount, or it could be a huge amount required depending on many different conditions. So considering that almost all standard reactions need heat put into them in order for them to get over the transition state, do you think there is a lot of energy for the food in the fridge? Also think about what temperature does something need for bacteria to grow? Just keep thinking along these lines. Do ask someone to do your homework for you, just simply ask someone for a couple of pointers or you will never learn these things.
Tough chemistry questions,any help?
A) Carbon reacts with oxygen to form two different compounds. compound I contains 4.82g carbon for every 6.44g of oxygen. compound II contains 20.13g carbon for every 53.7g of oxygen. what is the ratio of carbon to a fixed mass of oxygen for the two compounds B)Which state of matter is the most compressible ? and what is the least?
Tough Chemistry Question! Please help! Involving Molarity.?
35.00 mL x (1 L / 1000 mL) x (0.237 moles Ca(OH)2 / L) = 0.008295 moles Ca(OH)2 from balanced equation, 2 moles Ca(OH)2 ----> 1 mole CaCl2 0.008295 moles Ca(OH)2 x (1 mole CaCl2 / 2 moles Ca(OH)2 ) = 0.004148 moles CaCl2 finally... 0.004148 moles CaCl2 x (111.0 g CaCl2 / 1 mole CaCl2) = 0.460 g CaCl2
A tough chemistry question...?
in short - dust. dust of flour and coal burn easily and in the right concentrations, oxygen, dust and heat react violently. An explosion is nothing more than the rapid expansion of gas. Igniting coal or flour dust can cause the surrounding air to expand.
Very hard chemistry question help!! 10 points for correct answer with work?
the value of Kf for cyclohexane is -20 degrees celcius/m and its normal freezing point is 6.6 degrees celcius . a mass of 1.604g of a waxy solid dissolved in 10.000g of cyclohexane results in a freezing point of-4.4 degrees celcius. calculate the molar mass of the solid
Chemistry Help! (percent yield) one more time, this one is tough....?
this one is quite different of what i am aware of: C6H14 ---> C2H4 + other products if the yield of ethylene (C2H4) production is 42.5%. What mass of hexane(C6H14) must be to be produced 481 g of ethylene? -------------------------- My answer so the mm of C2H4 = 28.02 thus:481 g of C2H4 x (1 mol of C2H4 / 28.02 g of C2H4) = 17.17 mol of C2H4 then im stuck from here...
Tough Chemistry Problem, Please Help!?
first. 20.0 watts x (1 J/s / 1 watt) = 20.0 J/s next. E = ħc / λ E = energy of a single photon ħ = plancks constant = 6.626x10^-34 J s c = speed of light = 3.00x1-^8 m/s λ = 5.9 μm = 5.9x10^-6 m E = (6.626x10^-34 J s) x (3.00x10^8 m/s) / (5.9x10^-6 m) = 3.37x10^-20 J / photon finally, 20.0 J/s x (1 photon / 3.37x10^-20 J) = 5.94x10^20 photons / sec questions?
AP CHEMISTRY HELP!! STOICHIOMETRY!!!!! 9 Difficult questions!!!! PLEASE PLEASE PLEASE HELP!?
I have some chemistry questions that are so hard!! Please please please help! Please show the balanced equations as well 1. For the reaction N2 + 3H2 ---> 2NH3 How many moles of nitrogen are required to produce 500g of ammonia? 2. Sodium will react rather violently with water to produce sodium hydroxide and hydrogen gas. In this reaction, how many moles of hydrogen gas can be produced from 500 g of water? Assume that the sodium will react completely. 3. Carbon monoxide will react with an excess of oxygen to produce carbon dioxide. How many grams of carbon monoxide are needed to produce 20 moles of carbon dioxide? 4. Water can be decomposed into oxygen and hydrogen gas by running electricity through it. If a chemist starts with 3.25 x 10 to the third power mL of water, how many grams of oxygen gas can the reactions produce? (Hint: 1 mL of water = 1 gram of water) 5. Sulfur will react completely with excess oxygen to produce sulfur dioxide. How many grams of sulfur are needed to produce 800 g of sulfur dioxide? 6. Iron (II) will react with oxygen to produce iron (II) oxide. If 8.00 moles of iron react with excess oxygen, what mass of iron (II) oxide will be produced, in kg? 7. Cyclohexanol (C6 H12 O) is burned as a fuel. Assuming complete combustion, in the open air, how many moles of oxygen are needed to produce 13.7 moles of carbon dioxide? 8. Lead (II) nitrate will combine with potassium iodide to produce lead (II) iodide and potassium nitrate. How many milligrams of lead (II) iodide are produced from 300 g of potassium iodide with an excess of lead (II) nitrate? 9. Calculate the percentage yield for the reaction of methane (CH4) completely combusting with oxygen when 1000 g of methane reacts with an excess of oxygen gas to produce 2300 g of carbon dioxide.
How hard is the AP Chemistry test?
I got a 5 on the AP Chemistry exam from this last May.I found the multiple choice to be quite easy. The questions are, for the most part, purely conceptual. The math, if there is any, is not difficult by any objective measure. If you pay attention well in the class and ask for help on any questions you may have (or self-study vigorously and ask for help from a tutor or online if that is the route you are taking), the multiple choice section of the test should not be extremely difficult.In my opinion, the free response questions were significantly more difficult than the multiple choice questions. There are seven FRQs: three “long” ones that have a recommended working time of 23 minutes each, and four “short” ones that have a recommended working time of 9 minutes each. You have a total of 105 minutes to work on all of the FRQs.Here are a few points when it comes to working on the FRQs:Time management is extremely important.Spend the first three minutes making a plan of which questions you should answer first. Try not to spend any more time than three minutes doing this.Pace yourself with a silent watch (alarms are a big no-no).You don’t have to start with FRQ #1. If FRQ #1 is something that you draw a blank on, don’t stare at it mindlessly and waste time. Move on to a question you can answer. Don’t be afraid to answer them out of order.Did I already say time management?Clearly label all the steps you take in solving a problem in your answer booklet. Even if the question you are answering has a numerical answer, a little explanation cannot hurt, but try not to waste too much time explaining.If you have any questions, feel free to message me.
Is physical chemistry in the NEET very tough?
Hello friendsChemistry is one of the easiest and scoring subject if you clear your concept and practice properly .Physical chemistry is easiest part of chemistry because everything is known to you as questions are fixed . Like this topic this this question will come ….. just you have to practice all the questions available to that topic from your coaching module or some other good book.Practice daily 10–20 questions . And you will be able to solve all the questions related to physical chemistry .P.s revision is must of that questions . Don't try new question from that topic again and again just keep doing the same questionsBest of luck