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
natita [175]
3 years ago
8

The Earth's diameter at the equators is _____ its diameter at the poles. A:greater than B:equal to C:less than

Chemistry
1 answer:
Svetlanka [38]3 years ago
7 0
I think the answer is greater than
You might be interested in
Sulfur oxide is a main source of acid deposition. <br> a. True <br> b. False
ICE Princess25 [194]
True

The main chemicals in air pollution that create acid rain are sulfur dioxide (SO2) and nitrogen (NOx).
3 0
3 years ago
A mysterious white powder could be powdered sugar (C12H22O11), cocaine (C17H21NO4), codeine (C18H21NO3), norfenefrine (C8H11NO2)
rodikova [14]

Norfenefrine (C₈H₁₁NO₂).

<h3>Further explanation</h3>

We will solve a case related to one of the colligative properties, namely freezing point depression.

The freezing point of the solution is the temperature at which the solution begins to freeze. The difference between the freezing point of the solvent and the freezing point of the solution is called freezing point depression.

\boxed{ \ \Delta T_f = T_f(solvent) - T_f(solution) \ } \rightarrow \boxed{ \ \Delta T_f = K_f \times molality \ }

<u>Given:</u>

A mysterious white powder could be,

  • powdered sugar (C₁₂H₂₂O₁₁) with a molar mass of 342.30 g/moles,
  • cocaine (C₁₇H₂₁NO₄) with a molar mass of 303.35 g/moles,
  • codeine (C₁₈H₂₁NO₃) with a molar mass of 299.36 g/moles,
  • norfenefrine (C₈H₁₁NO₂) with a molar mass of 153.18 g/moles, or
  • fructose (C₆H₁₂O₆) with a molar mass of 180.16 g/moles.

When 82 mg of the powder is dissolved in 1.50 mL of ethanol (density = 0.789 g/cm³, normal freezing point −114.6°C, Kf = 1.99°C/m), the freezing point is lowered to −115.5°C.

<u>Question: </u>What is the identity of the white powder?

<u>The Process:</u>

Let us identify the solute, the solvent, initial, and final temperatures.

  • The solute = the powder
  • The solvent = ethanol
  • The freezing point of the solvent = −114.6°C
  • The freezing point of the solution = −115.5°C

Prepare masses of solutes and solvents.

  • Mass of solute = 82 mg = 0.082 g
  • Mass of solvent = density x volume, i.e., \boxed{ \ 0.789 \ \frac{g}{cm^3} \times 1.50 \ cm^3 = 1.1835 \ g = 0.00118 \ kg  \ }

We must prepare the solvent mass unit in kg because the unit of molality is the mole of the solute divided by the mass of the solvent in kg.

The molality formula is as follows:

\boxed{ \ m = \frac{moles \ of \ solute}{kg \ of \ solvent} \ } \rightarrow \boxed{ \ m = \frac{mass \ of \ solute \ (g)}{molar \ mass \ of \ solute \times kg \ of \ solvent} \ }

Now we combine it with the formula of freezing point depression.

\boxed{ \ \Delta T_f =  K_f \times \frac{mass \ of \ solute \ (g)}{molar \ mass \ of \ solute \times kg \ of \ solvent} \ }

It is clear that we will determine the molar mass of the solute (denoted by Mr).

We enter all data into the formula.

\boxed{ \ -114.6^0C - (-115.5^0C) = 1.99 \frac{^0C}{m} \times \frac{0.082 \ g}{Mr \times 0.00118 \ kg} \ }

\boxed{ \ 0.9 = \frac{1.99 \times 0.082}{Mr \times 0.00118} \ }

\boxed{ \ Mr = \frac{0.16318}{0.9 \times 0.00118} \ }

We get \boxed{ \ Mr = 153.65 \ }

These results are very close to the molar mass of norfenefrine which is 153.18 g/mol. Thus the white powder is norfenefrine.

<h3>Learn more</h3>
  1. The molality and mole fraction of water brainly.com/question/10861444
  2. About the mass and density of ethylene glycol as an  antifreeze brainly.com/question/4053884
  3. About the solution as a homogeneous mixture  brainly.com/question/637791

Keywords: a mysterious white powder, sugar, cocaine, codeine, norfenefrine, fructose, the solute, the solvent, dissolved, ethanol, normal freezing point, the freezing point depression, the identity

7 0
3 years ago
Read 2 more answers
Marie discovers boxes of elements in a storage room. The boxes do not say which elements they contain, but they do have informat
elena-s [515]

The reactivity of metals increases as you move left in a period and as you move down in a group, so Marie needs to know the period and group of the element inside each box. Boxes that show locations in groups 1 or 2 or in period 8 contain the most reactive elements.

7 0
3 years ago
Read 2 more answers
I created a typical vinegar and baking soda experiment. About 100 ml of white vinegar, and 100ml of baking soda. Once the reacti
olganol [36]
It is 20 because then you will put 30 inside of 20milimeeter and put 70 years into the other pint and put it learnt into the cup
7 0
2 years ago
8.
Dima020 [189]
The correct answer is b hope this helps air
5 0
2 years ago
Other questions:
  • If 0.0262 mol of cacl2 is dissolved in water to make a 0.520 m solution, what is the volume of the solution?
    13·1 answer
  • Which element has an atom with the greatest tendency to attract electrons in a chemical bond?
    6·2 answers
  • Which of the following is a change from a less condensed to a more condensed state of matter?
    13·1 answer
  • How many significant digits are in 0.0038020 ?
    9·1 answer
  • Tcs food that stay in the tempature danger zone for 4 hours or longer
    14·1 answer
  • How many moles are in 68 grams of copper (ll) hydroxide, Cu(OH)2
    5·2 answers
  • Convert 3.9x10^5mg to dg
    9·2 answers
  • How to treat stream water for drinking
    6·1 answer
  • As the concentration of a KOH solution increases, the number of moles of HCl needed to neutralize the KOH solution?
    8·1 answer
  • How does the concentration of a gas in solution change when the partial pressure of the gas above the solution increases?
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!