PLZ HELP Organisms on earth are ________ based life forms. - oxygen - hydrogen

When 70.4 g of benzamide (C7H7NO) are dissolved in 850. g of a certain mystery liquid X, the freezing point of the solution is 2

Arlecino [84]

Answer:

1.62

Explanation:

From the given information:

number of moles of benzamide $=\dfrac{70.4 \ g}{121.14 \ g/mol}$

= 0.58 mole

The molality = $\dfrac{mass \ of \ solute (i.e. \ benzamide )}{mass \ of \ solvent }$

$= \dfrac{0.58 }{0.85 }$

= 0.6837

Using the formula:

$\mathbf {dT = l \times k_f \times m}$

where;

dT = freezing point = 27

l = Van't Hoff factor = 1

kf = freezing constant of the solvent

∴

2.7 °C = 1 × kf × 0.6837 m

kf = 2.7 °C/ 0.6837m

kf = 3.949 °C/m

number of moles of NH4Cl = $\dfrac{70.4 \ g}{53.491 \ g /mol}$

= 1.316 mol

The molality = $\dfrac{1.316 \ mol}{0.85 \ kg}$

= 1.5484

Thus;

the above kf value is used in determining the Van't Hoff factor for NH4Cl

i.e.

9.9 = l × 3.949 × 1.5484 m

$l = \dfrac{9.9}{3.949 \times 1.5484 \ m}$

l = 1.62

5 0

3 years ago

Which describes how radiation moves?

vazorg [7]

Hey wademcelroy2005, thanks for submitting your question to Brainly!

The answer to your question is B:Radiation moves from a warmer object to a cooler object

4 0

3 years ago

Read 2 more answers

A 0.964 gram sample of a mixture of sodium formate and sodium chloride is analyzed by adding sulfuric acid. The equation for the

frosja888 [35]

Answer: 67.8 %.

Explanation:

Okay, let us delve right into the solution to the question;

The balanced chemical reaction is given by the equation (1) below;

2 HCOONa + H2SO4 ---------> 2 CO + 2 H2O + Na2SO4. ----------------------------------------------------------------------------(1).

From the balanced chemical reaction in equation (1) above we can see that; 2 moles of HCOONa reacts with one moles of tetraoxosulphate acid, H2SO4 to produce 2 moles of carbonmonoxide,CO; 2 moles of water, H2O and 1 mole of sodium tetraoxosulphate, Na2SO4.

The parameters given from the question are; total atmospheric pressure, P(t) = 752 torr, volume of CO= 242 mL = 0.242 Litres.

STEP ONE : find the carbon monoxide,CO pressure; P(CO).

Using the formula below;

P(t) = P(CO) + P(H2O). Hence;

P(CO) = P(t) - P(H2O). Note that P(H2O)= 19.8 torr.

==>P(CO)= 752 torr - 19.8 torr = 732.2 torr.

STEP TWO: calculate the number of moles of Carbonmonoxide,CO.

Using the formula below;

Number of moles= pressure(P) × volume(v) / gas constant(R) × temperature (T).

That is, n= PV/RT.

n= 732 torr × 0.242 Litres/ 62.4 × 295.15.

= 9.62 × 10^-3 mol of CO.

STEP THREE:

2 moles of HCOONa = 2 moles of CO.

=> 2 moles of HCOONa = 2 moles of CO/ 2 moles of CO = 1 mol( HCOONa/ CO).

Then, 9.62 × 10^-3 mol of CO × 1 mol( HCOONa/ CO).

==> 9.62 × 10^-3 mol HCOONa × molar masss of HCOONa(68 grams/mol)

= 0.654 grams.

Therefore, the percentage of sodium formate in the original mixture = 0.654 grams/ 0.964 gram × 100 = 67.8 %.

5 0

3 years ago

Solid a is a very hard electrical insulator in solid as well as in molten state and melts at extremely high temperature. What ty

velikii [3]

This is covalent network type of solid.

For example, silicon dioxide (SiO₂) is covalent network solid with covalent bonding.

Covalent network solid is a chemical compound (or element) in which the atoms are bonded by covalent bonds in a continuous network extending throughout the material.

Silicon(IV) oxide has continuous three-dimensional network of SiO₂ units and diamond has sp3 hybridization.

This solids do not have free electrons so they are good insulators.

They have strong covalent bonds, so they melt at extremely high temperature.

Other examples are quartz, diamond, and silicon carbide.

More about network solid: brainly.com/question/15548648

#SPJ4

3 0

2 years ago

What element has a total of 3 p-sublevel electrons?

den301095 [7]

Elements with three p-electrons....

That would be N, P, As, Sb, and Bi -- elements in group 15

For example, energy diagram showing "empty" orbitals up through the 3p.

.....3p __ __ __

3s __

.....2p __ __ __

2s __

1s __

Energy diagram of phosphorous showing three unpaired electrons in 3p-sublevel

.....3p ↑_ ↑_ ↑_

3s ↑↓

.....2p ↑↓ ↑↓ ↑↓

2s ↑↓

1s ↑↓

According to Hund's rule, the electrons singly occupy the p-orbitals, and all have the same spin.

8 0

3 years ago

PLZ HELP Organisms on earth are ________ based life forms. - oxygen - hydrogen - carbon