Examples of nucliec tides

Will you obtain a pure solid in evaporation technique? Justify your answer

aniked [119]

Evaporation technique is used to separate a compound dissolved in a solvent by vaporizing the solvent and converting it to gaseous state. This leaves behind the solid residue present in the solution after the pure solvent is vaporized. The solvent vapors can be collected and condensed to get pure solvent. But the solid residue cannot be considered pure as it is the left over solid after all the solvent is evaporated. If the solution has some impurities, the solid left over includes all of the impurities. So, we cannot obtain a pure solid in evaporation technique.

3 0

3 years ago

Calculate the number of atoms of H in 22.5g of H2O

Marta_Voda [28]

2.5gm answer ....2/18x22.5

3 0

2 years ago

(b) Use the first law of thermodynamic to calculate AU for the following situations: (i) A coiled spring unwinds producing 153 J

il63 [147K]

Answer:

(i) ΔU = 116 J

(ii) ΔU = 289 J

(iii) ΔU = 1 KJ

(iv) ΔU = 0 J

(v) ΔU = 3.25 KJ

Explanation:

first law:

ΔU = Q + W

(i) W = 153 J; Q = - 37 J ( Q ( - ), losing friction )

⇒ ΔU = 153 - 37 = 116 J

(ii) W = 289 J; Q = 0 ( insulated)

⇒ ΔU = W = 289 J

(iii) Q = 1 KJ , W = 0 ( isovolumetric process)

⇒ ΔU = Q = 1 KJ

(iv) isothermal ( constant temperature )

ΔU = Cv * ΔT

∴ ΔT = 0° ( isothermal )

⇒ ΔU = 0 J

(v) isobaric ( constant pressure )

⇒ ΔU = Q + W

∴ Q = 15.6 KJ

∴ W = - ∫ P dV = - P ΔV; W (-) the system performs a job and the volume increases

.

∴ P = 950 KPa * ( 1000 Pa / KPa ) = 950000 Pa = 950000 J/m³

∴ ΔV = 18 - 5 = 13 L * ( m³ / 1000 L ) = 0.013 m³

⇒ W = - ( 950000 J/m³) * ( 0.013 m³ ) = - 12350 J ( - 12.35 KJ )

⇒ ΔU = 15.6 KJ + ( - 12.35 KJ )

⇒ ΔU = 3.25 KJ

7 0

3 years ago

The density of mercury is 13.6 g/cm'. How many quarts does 83.0 g of Hg occupy? (1 L=1.06 qt)

forsale [732]

Answer:

0.0064 qt

Explanation:

Given data:

Density of mercury = 13.6 g/cm³

Mass of mercury = 83.0 g

How many quarts mercury have = ?

Solution:

First of all we will calculate the volume in cm³.

d = m/v

13.6 g/cm³ = 83.0 g / volume

Volume = 83.0 g / 13.6 g/cm³

Volume = 6.1 cm³

cm³ to L:

6.1 cm³ × 1 L / 1000 cm³

0.0061 L

In quarts:

1 L = 1.06 qt

0.0061 L × 1.06 qt / 1 L

0.0064 qt

4 0

3 years ago

Predict the products of the reaction below. That is, complete the right hand side of the chemical equation. Be sure your equatio

pickupchik [31]

Answer:

2 HClO₃ + Ca(OH)₂ ---> Ca(ClO₃)₂ + 2 H₂O

Explanation:

This is a double-displacement reaction. In these reactions, the cation of one molecule swaps with the cation of another.

In this case, the hydrogen cation (H⁺) from HClO₃ swaps with the calcium cation (Ca²⁺) of Ca(OH)₂. When writing the products, keep the charges of the ions in mind. The products must be neutral, so some will need to have more than 1 cation/anion.

The unbalanced equation:

HClO₃ + Ca(OH)₂ ---> Ca(ClO₃)₂ + H₂O

Reactants: 3 hydrogen, 1 chlorine, 5 oxygen, 1 calcium

Products: 2 hydrogen, 2 chlorine, 7 oxygen, 1 calcium

The balanced equation:

2 HClO₃ + Ca(OH)₂ ---> Ca(ClO₃)₂ + 2 H₂O

Reactants: 4 hydrogen, 2 chlorine, 8 oxygen, 1 calcium

Products: 4 hydrogen, 2 chlorine, 8 oxygen, 1 calcium

4 0

2 years ago