Significant digits are the number of digits that reflect the precision of a measurement or number. true or false

A certain substance X has a normal freezing point of -6.4 C and a molal freezing point depression constant Kf= 3.96 degrees C.kg

Brut [27]

Answer: $1.0\times 10^2g$

Explanation:

Depression in freezing point is given by:

$\Delta T_f=i\times K_f\times m$

$\Delta T_f=T_f^0-T_f=(-6.4-(13.6))^0C=7.2^0C$ = Depression in freezing point

i= vant hoff factor = 1 (for non electrolyte like urea)

$K_f$ = freezing point constant = $3.96^0C/m$

m= molality

$\Delta T_f=i\times K_f\times \frac{\text{mass of solute}}{\text{molar mass of solute}}\times \text{weight of solvent in kg}}$

Weight of solvent (X)= 950 g = 0.95 kg

Molar mass of non electrolyte (urea) = 60.06 g/mol

Mass of non electrolyte (urea) added = ?

$7.2=1\times 3.96\times \frac{xg}{60.06 g/mol\times 0.95kg}$

$x=1.0\times 10^2g$

Thus $1.0\times 10^2g$ urea was dissolved.

8 0

3 years ago

In general, ionic compounds are hard solids at ambient temperatures but they shatter fairly easily. How do these two properties

lord [1]

Ionic or electrovalent compounds support the theory of ionic bonding because they are compounds composed of charged particles formed when an atom gains or loses electrons.

Electrovalent compounds posses:

High boiling and melting points.
Form crystals.

<h3>What is ionic bonding?</h3>

This is the transfer of valence electrons from metals to non metals to form ionic compounds. It also refers to a chemical bond formed between two ions with opposite charges.

Learn more about ionic compounds:

brainly.com/question/18246121

7 0

2 years ago

What is a physical intensive property?

Len [333]

An intensive property is a property that does not change depending on how much mass of it you are considered. An example of an intensive property is density. No matter how much water you examine, the density of the sample will be 1g/cm³.

6 0

2 years ago

Arrange the procedural steps, from start to finish, that are required to prepare indigo from nitrobenzaldehyde and acetone in ba

lions [1.4K]

Acetone has α-hydrogens (on both sides) and thus can be deprotonated to give a nucleophilic enolate anion. The aldehyde carbonyl is much more electrophilic than that of a ketone, and therefore reacts rapidly with the enolate.

<h3>What is nitrobenzaldehyde?</h3>

Synthesis. The synthesis of 3-nitrobenzaldehyde is achieved via nitration of benzaldehyde, which yields especially the meta-isomer. Creation allocation is about 19% for the ortho-, 72% for the meta- and 9% for the para isomers.

Acetone, propanone, or dimethyl ketone, is an organic combination with the formula (CH3)2CO. It is the easiest and smallest ketone. It is a colorless, highly volatile, and combustible liquid with a characteristic aromatic odor.

Nitration of benzene with conc nitric acid and conc sulphuric acid gives nitrobenzene. Chlorination with chlorine in the existence of anhydrous aluminum chloride gives meta nitro chlorobenzene.

To learn more about sulphuric acid, refer to:

brainly.com/question/4018599

#SPJ4

5 0

1 year ago

Carbon monoxide (CO) reacts with hydrogen (H2) to form methane (CH4) and water (H2O).

Artemon [7]

Answer:

5.9x10^-2 M

Explanation:

Step 1:

Data obtained from the question. This includes the following:

Concentration of CO, [CO] = 0.30 M

Concentration of H2, [H2] = 0.10 M

Concentration of H2O, [H2O] = 0.020 M

Equilibrium constant, K = 3.90

Concentration of CH4, [CH4] =..?

Step 2:

The balanced equation for the reaction. This is given below:

CO(g) + 3H2(g) <=> CH4(g) + H2O(g)

Step 3:

Determination of the concentration of CH4.

The expression for equilibrium constant of the above equation is given below:

K = [CH4] [H2O] / [CO] [H2]^3

3.9 = [CH4] x 0.02/ 0.3 x (0.1)^3

Cross multiply to express in linear form

[CH4] x 0.02= 3.9 x 0.3 x (0.1)^3

Divide both side by 0.02

[CH4] = 3.9 x 0.3 x (0.1)^3 /0.02

[CH4] = 5.9x10^-2 M

Therefore, the equilibrium concentration of CH4 is 5.9x10^-2 M

5 0

2 years ago