Here we have to get the correct statements among the given, applicable for Diels-Alder reaction.
The true statements in case Diels-Alder reaction are-
1. An excess of Maleic anhydride is used.
2. The I.R. of the products are indistinguishable.
The Diels-Alder reaction is the most is the most important cyclo-addition reaction in organic chemistry. These are addition reactions in which ring systems are formed without eliminating any compounds.
There remains one diene and one dienophile. The reaction is reversible in nature and requires elevated temperature to obtain its transition state. The reaction rate become faster in certain condition like using of polar solvents.
Among the given statements the following statements are true-
1. An excess of maleic anhydride (the most effective di-enophile) is used to process the reaction in forward direction.
2. The products obtain in this reaction are stereoisomers thus are indistinguishable by infrared spectroscopy (IR).
The statements which are not true for the Diels-Alder reaction:
3. The re-crystallization of the products by any polar solvent like methanol is not feasible as it will cause the retro reaction due to stability of the transition state in polar solvent.
4. Cleaning of glassware are compulsory for any reaction it is not specifically true for Diels-Alder reaction.
5. The reaction occurs at elevated temperature thus flame is required.
I can’t access the pictures. Sorry!
<span>Answer:
For this problem, you would need to know the specific heat of water, that is, the amount of energy required to raise the temperature of 1 g of water by 1 degree C. The formula is q = c X m X delta T, where q is the specific heat of water, m is the mass and delta T is the change in temperature. If we look up the specific heat of water, we find it is 4.184 J/(g X degree C). The temperature of the water went up 20 degrees.
4.184 x 713 x 20.0 = 59700 J to 3 significant digits, or 59.7 kJ.
Now, that is the energy to form B2O3 from 1 gram of boron. If we want kJ/mole, we need to do a little more work.
To find the number of moles of Boron contained in 1 gram, we need to know the gram atomic mass of Boron, which is 10.811. Dividing 1 gram of boron by 10.811 gives us .0925 moles of boron. Since it takes 2 moles of boron to make 1 mole B2O3, we would divide the number of moles of boron by two to get the number of moles of B2O3.
.0925/2 = .0462 moles...so you would divide the energy in KJ by the number of moles to get KJ/mole. 59.7/.0462 = 1290 KJ/mole.</span>
The balanced equation for combustion is as follows;
2CH₃OH + 3O₂ ---> 2CO₂ + 4H₂O
The stoichiometry of CH₃OH to O₂ is 2:3
the limiting reagent is the reactant that is fully consumed during the reaction. The amount of product formed is directly proportional to the amount of limiting reactant produced. The excess reagent is the reactant that is provided in excess and is not fully used up, there will be an amount of this reagent remaining after the reaction.
If methanol is the limiting reactant,
If 2 mol of methanol reacts with 3 moles of O₂
Then 24 mol of methanol reacts with - 3/2 x 24 = 36 mol of O₂ should be present
But only 15 mol of O₂ is present, therefore O₂ is the limiting reactant and methanol is in excess.
3 mol of O₂ reacts with 2 mol of CH₃OH
then 15 mol of O₂ reacts with 2/3 x 15 = 10 mol of CH₃OH
Excess reactant is methanol, 10 mol are used up therefore 24 - 10 mol = 14 mol are remaining at the end of the reaction
Answer:
This question is incomplete and unclear; the complete question including the missing part is:
Emelie is working on a science project. Her task is to answer the question:
"Does Rogooti (a hair cream sold on TV) affect the speed of hair growth
(in length)". Her family is willing to volunteer for the experiment. Identify the control group (CG) and the independent and dependent variables.
ANSWER:
Independent variable: Rogooti hair cream
Dependent variable: Speed of hair growth/length
Control group: Family members that do not use the Rogooti hair cream
Explanation:
In an experiment, the independent variable is the variable that the experimenter changes or manipulates in order to bring about a measurable response. In this case, the ROGOOTI HAIR CREAM is the independent variable.
Dependent variable refers to the variable that is measured or the variable that responds to the change made to the independent variable. In this case, the dependent variable is SPEED AT WHICH HAIR GROWS (IN LENGTH).
Control group in an experiment is the group that does not receive the experimental treatment. In this case, the experimental treatment is the Rogooti hair cream, hence, the control group will be the VOLUNTEER FAMILY MEMBERS THAT DOES NOT RECEIVE THE ROGOOTI HAIR CREAM ON THEIR HAIR.
