HSC Science (Electronics) 12th Standard Board Exam - Maharashtra State Board Question Bank Solutions

Which stoichiometric defect does not change the density of the crystal?

Which stoichiometric defect decreases the density of the crystal?

test q 1234

Answer the following.

List the uses of Neon and argon gases.

What are fuel cells?

Calculate ΔH° for the reaction between ethene and water to form ethyl alcohol from the
following data:

ΔcH° C₂H₅OH_(l) = -1368 kJ
ΔcH° C₂H_4(g) = -1410 kJ
Does the calculated ΔH° represent the enthalpy of formation of liquid ethanol?

Calculate the standard enthalpy of combustion of CH₃COOH(l) from the following data:

`Delta_fH^@(CO_2)=-393.3 kJ mol^-1`

`Delta_fH^@(H_2O)=-285.8 kJ mol^-1`

`Delta_fH^@(CH_3COOH)=-483.2 kJ mol^-1`

What is the action of concentrated sulphuric acid on phosphorous pentachloride

Define osmotic pressure.

What will be the action of the mixture of sodium nitrite and dilute hydrochloric acid on aniline

What will be the action of the mixture of sodium nitrite and dilute hydrochloric acid on diethyl amine

What will be the action of the mixture of sodium nitrite and dilute hydrochloric acid on triethyl amine

Schottky defects are observed in which solid among the following?

(a) Brass

(b) Cesium Chloride

(c) Zinc sulphide

(d) Stainless steel

What happens when dilute sulphuric acid is treated with Fe

What happens when dilute sulphuric acid is treated with CaF₂

Calculate the standard enthalpy of the reaction, 2C(graphite) + 3H_2(g) → C₂H_6(g), ΔH° = ?

From the following ΔH° values

a) `C_2H_6(g) + 7/2 O_2(g) -> 2CO_2(g) + 3H_2 O(l)`.  ΔH° = -1560kJ

b) `H_2(g) + 1/2 O_2 (g) -> H_2O(l)`  ΔH° = -285.8kJ

c) C(graphite) + O₂(g) -> CO₂(g). ΔH° = -393.5kJ

Write reactions involved in preparation of potassium dichromate from chrome iron ore

Calculate ∆H° for the following reaction:

2H₃BO_3(aq) → B2O_3(s) + 3H₂O_(l)

a) H₃BO_3(aq) → HBO_2(aq) + H₂O_(l) , ∆`H_1^@` = − 0.02 kJ

b) H₂B₄O_7(s) → 2B₂O_3(s) + H₂O_(l) , ∆`H_2^@` = 17.3 kJ

c)H₂B₄O_7(s) + H₂O_(l) → 4HBO_2(aq), ∆`H_3^@` = − 11.58 kJ

What are Frenkel defect

Write electronic configuration and two uses of neon. (Z = 10)