What structure do insects have for breathing (A) gills (B) tracheae (C) skin (D) lungs

A 4.305-g sample of a nonelectrolyte is dissolved in 105 g of water. the solution freezes at -1.23c. calculate the molar mass of

amid [387]

The answer is 62.00 g/mol.
Solution:
Knowing that the freezing point of water is 0°C, temperature change Δt is
Δt = 0C - (-1.23°C) = 1.23°C
Since the van 't Hoff factor i is essentially 1 for non-electrolytes dissolved in water, we calculate for the number of moles x of the compound dissolved from the equation
Δt = i Kf m
1.23°C = (1) (1.86°C kg mol-1) (x / 0.105 kg)
x = 0.069435 mol
Therefore, the molar mass of the solute is
molar mass = 4.305g / 0.069435mol = 62.00 g/mol

6 0

3 years ago

How many grams are in a sample of 0.55 mol of K?

Katyanochek1 [597]

The equation you use here is
mass =moles x Mr

So:
Moles of K - 0.55mol
Mr of K - 39.1

Mass= 0.55x39.1 =21.505g

4 0

3 years ago

Which part of a feedback mechanism causes change to make up for the departure from the set point? A. sensor B. effector C. respo

koban [17]

I would have to say C. Response.

5 0

4 years ago

Read 2 more answers

Gaseous butano (CH,(CH),CH) will react with gaseous oxygen (0) to produce gaseous carbon dioxide (CO2) and goseous woter (11,0).

slega [8]

Answer:

Firstly, We have to convert it in the Miles formula...

No. of moles = Mass given/Molar Mass

So, the final answer be come

<h3> Ans - 50.8 gm and there same % is 50.8% butane in reaction </h3>

5 0

2 years ago

Find the vapor pressure of a water solution in which the

zheka24 [161]

Answer:

The vapor pressure in solution is 0,0051 atm

Explanation:

This is the formula for vapor pressure lowering, the colligative property.

P vapor = Pressure sv pure . Xsv

Where Xsv is data.

Xsv means Molar fraction (moles solvent/total n° moles)

Vapor pressure of water, pure is 17.5 mmHg

P vapor = 0,0313 atm . 0163

P vapor in solution = 0,0051 atm

Molar fraction does not have units

A solution will have less vapor pressure than that observed in the pure solvent.

5 0

3 years ago