1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
kakasveta [241]
3 years ago
11

If a sample contains 70.0 % of the R enantiomer and 30.0 % of the S enantiomer, what is the enantiomeric excess of the mixture?

Chemistry
1 answer:
NeTakaya3 years ago
3 0

Answer:

the enantiomeric excess of the mixture is 40%

Explanation:

The computation of the enantiomeric excess of the mixture is shown below:

As we know that

= |\frac{R - S}{R + S} |\times 100\\\\= |\frac{70 - 30}{70 + 30}| \times 100\\\\= 40\%

Hence, the enantiomeric excess of the mixture is 40%

You might be interested in
4. A student started with a 0.032 g sample of copper which he took through the series of reactions described in this experiment.
Elodia [21]

Answer:

Y=48.6\%

Explanation:

Hello,

In this case, we can consider the following chemical reaction for the oxidation of copper which only occurs at high temperatures:

2Cu+O_2\rightarrow 2CuO

In such a way, for 0.032 grams of copper, the following grams of copper (II) oxide (black product) are yielded:

m_{CuO}=0.032gCu*\frac{1molCu}{63.546gCu} *\frac{2molCuO}{2molCu}*\frac{79.546gCuO}{1molCuO}  =0.078gCuO

Therefore, the percent yield is:

Y=\frac{0.038g}{0.078g}*100\%\\ \\Y=48.6\%

Best regards.

6 0
3 years ago
a 4.18 g sample of a hydrocarbon is combusted in a bomb calorimeter that contains 974 g of water. the temperature of the water i
lys-0071 [83]

The heat of the reaction, in kJ, when 4.18 g of the hydrocarbon are combusted 775.70 kJ.

The heat energy is given as :

q = m c ΔT + Ccal ΔT

q = ( 974 g× 4.184 ×6.9) + 624 ×6.9

q = 32424.59 J

moles of hydrocarbon = 0.0418 mol

heat of combustion = 32424.59 J / 0.0418 mol

                                 = 775707.89 J

                                = 775.70 kJ

Thus, A 4.18 g sample of a hydrocarbon is combusted in a bomb calorimeter that contains 974 g of water. the temperature of the water increases by 6.9 °C when the hydrocarbon is combusted. the calorimeter constant for the calorimeter was determined to be 624 J/°C. what is the heat of the reaction is 775.70 kJ.

To learn more about calorimeter here

brainly.com/question/28943378

#SPJ4

5 0
1 year ago
Evaluate three communication skills that can assist you in sustaining positive relationships​
Tpy6a [65]

1. Accept and celebrate differences. One of the biggest challenges we experience in relationships is that we are all different. We can perceive the world in many ways. Certainly astumbling block that we come across when we try to build relationships is a desire or an expectation that people will think like we do and, in this way, it is so much easier to create a rapport. We feel more comfortable when we feel that people “get” us and can see our point of view. Life, however, would be very dull if we were all the same and, while we may find it initially easier, the novelty of sameness soon would wear off. So accepting and celebrating that we are all different is a great starting point.

2. Listen effectively. Listening is a crucial skill in boosting another person’s self-esteem, the silent form of flattery that makes people feel supported and valued. Listening and understanding what others communicate to us is the most important part of successful interaction and vice versa.

Active or reflective listening is the single most useful and important listening skill. In active listening, we also are genuinely interested in understanding what the other person is thinking, feeling, wanting, or what the message means, and we are active in checking out our understanding before we respond with our own new message. We restate or paraphrase our understanding of their message and reflect it back to the sender for verification. This verification or feedback process is what distinguishes active listening and makes it effective.

3. Give people your time. Giving time to people is also a huge gift. In a world where time is of the essence and we are trying to fit in more than one lifetime, we don’t always have the time to give to our loved ones, friends, and work colleagues. Technology has somewhat eroded our ability to build real rapport and we attempt to multi-task by texting and talking at the same time.

Being present in the time you give to people is also important, so that, when you are with someone, you are truly with someone and not dwelling in the past or worrying about the future. The connection we make with other people is the verytouchstone of our existence, and devoting time, energy, and effort to developing and building relationships is one of the most valuable life skills.

3 0
3 years ago
What are the symbols for the elements with the following valence electron configurations? List all.a. s2d1b. s2p3c. s2p
maria [59]

Answer:

Sc : 4s 2 3d 1

 Y : l 5s 2 4d 1

La : 6s 2 5d 1

Ce : 6s 2 4f 1 5d 1

Gd : 6s 2 4f 7 5d 1

Lu : 6s 2 4f 14 5d 1

Ac : 7s 2 6d 1

Pa : 7s 2 5f 2 6d 1

U : l 7s 2 5f 3 6d 1

Np : 7s 2 5f 4 6d 1

Cm : 7s 2 5f 7 6d 1

b. s2p3

he pnictogens:

N l : 2s 2 2p 3

P l : 3s 2 3p 3

As : 4s 2 3d 10 4p 3

Sb : 5s 2 4d 10 5p 3

Bi : 6s 2 4f 14 5d 10 6p 3

Mc : 7s 2 5f 14 6d 10 7p 3

c.The noble gases:

Ne : 2s 2 2p 6

Ar : 3s 2 3p 6

Kr : 4s 2 3d 10 4p 6

Xe : 5s 2 4d 10 5p 6

Rn : 6s 2 4f 14 5d 10 6p 6

Og : 7s 2 5f 14 6d 10 7p 6

Explanation: From the periodic tables we can drive elements with the electronic configuration

Sc : 4s 2 3d 1

 Y : l 5s 2 4d 1

La : 6s 2 5d 1

Ce : 6s 2 4f 1 5d 1

Gd : 6s 2 4f 7 5d 1

Lu : 6s 2 4f 14 5d 1

Ac : 7s 2 6d 1

Pa : 7s 2 5f 2 6d 1

U : l 7s 2 5f 3 6d 1

Np : 7s 2 5f 4 6d 1

Cm : 7s 2 5f 7 6d 1

b. s2p3

he pnictogens:

N l : 2s 2 2p 3

P l : 3s 2 3p 3

As : 4s 2 3d 10 4p 3

Sb : 5s 2 4d 10 5p 3

Bi : 6s 2 4f 14 5d 10 6p 3

Mc : 7s 2 5f 14 6d 10 7p 3

c.The noble gases:

Ne : 2s 2 2p 6

Ar : 3s 2 3p 6

Kr : 4s 2 3d 10 4p 6

Xe : 5s 2 4d 10 5p 6

Rn : 6s 2 4f 14 5d 10 6p 6

Og : 7s 2 5f 14 6d 10 7p 6

3 0
3 years ago
The atmosphere is about 21% oxygen. At a pressure of 749 torr, what is the partial pressure of O2?
Kitty [74]

Answer:

157.29 Torr

Explanation:

This question may be solved by the mole fraction.

Mole fraction → Moles of gas / Total moles = Partial pressure of gas / Total pressure

If the atmosphere is about 21% you assume that the mole fraction is 0.21 so:

0.21 = Partial pressure of gas / Total pressure

0.21 = Partial pressure of gas / 749 Torr

Partial pressure of the gas = 749 Torr . 0.21 →  157.29 Torr

3 0
3 years ago
Other questions:
  • Match the following vocabulary terms to their definitions. 1 . amount of energy required to change 1 gram of material from the s
    6·1 answer
  • Engineering applies blank And math to develop technology
    15·1 answer
  • Two characteristics of radiowaves​
    6·1 answer
  • What are the respective concentrations (moles/liter) of k+ and po43- afforded by dissolving 0.800 mol k3po4 in water and dilutin
    8·1 answer
  • Calculate the density of carbon dioxide at STP
    15·1 answer
  • Collision theory states that as molecules or ions bump into each other, a reaction will only occur if the collision has the corr
    9·1 answer
  • Which is the BEST definition for a chemical ? *
    10·1 answer
  • Does someone know the combustion in a jacket potato???
    8·1 answer
  • Why are intensive properties useful for identifying a subtenant?
    9·1 answer
  • The water-gas shift reaction plays a central role in the chemical methods for obtaining cleaner fuels from coal:CO(g) + H₂O(g) ⇄
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!