Seema takes three beakers A, B and C filled with aqueous solution of glucose, alcohol and hydrochloric acid respectively as shown in the following figure:
![](/assets/questions/media/145526-30884-1602755623.jpg)
(i) State your observation in terms of glowing of bulb when the switch is ON.
(ii) Justify your observations by giving reason for each case.
(iii) Mention the change noticed with appropriate reason if the content of beaker B is replaced by NaOH solution."
i> Bulb A and Bulb B do not glow when the switch is on but Bulb C glows.
ii> Glucose (Beaker A) and Alcohol (Beaker B) do not conduct electricity as they do not dissociate into ions.
Dilute HCl (Beaker C) dissociates to form ions H+ and Cl-, hence the current flows through it and the bulb glows.
$HCl\leftrightarrows \ H^{+} \ +\ Cl^{-}$
iii> If alcohol is replaced by NaOH solution in the beaker B, then we observe that the bulb Glows in beaker B as NaOH dissociates into ions.
$NaOH\leftrightarrows \ Na^{+} \ +\ OH^{-}$
Related Articles
- (a) What happens when propanoic acid is warmed with methanol in the presence of a few drops of concentrated sulphuric acid? Write equation of the reaction involved.(b) What change will you observe if you test soap solution with a litmus paper (red and blue)? Give reason for your observation.(c) What is meant by denatured alcohol? What is the need to denature alcohol?
- What happens when a solution of an acid is mixed with a solution of a base in a test tube?The temperature of the solution increasesThe temperature of the solution decreasesThe temperature of the solution remains the sameSalt formation takes place(a) (i) only(b) (i) and (iii)(c) (ii) and (iii)(d) (i) and (iv)
- Three beakers labelled as A, B and C each containing 25 ml of water were taken. A small amount of NaOH, anhydrous CuSO4 and NaCl were added to the beakers A, B and C respectively. It was observed that there was an increase in the temperature of the solution contained in beakers A and B, whereas in case of beaker C, the temperature of the solution falls. Which one of the following statement(s) is (are) correct?(i) In beakers A and B, exothermic process has occurred.(ii) In beakers A and B, endothermic process has occuBftd.(iii) In beaker C exothermic process has occurred.(iv) In beaker C endothermic process has occurred.
- What happens when a solution of an acid is mixed with a solution of a base in a test tube?(i) Temperature of the solution decreases(ii) Temperature of the solution increases (iii) Temperature of the solution remains the same(iv) Salt formation takes place(a) (i) and (iv) (b) (i) and (ii) (c) (ii) only (d) (i) and (iv)
- Three beakers labeled as A, B and C each containing 25 mL of water were taken. A small amount of NaOH, anhydrous CuSO4 and NaCl were added to the beakers A, B and C respectively. It was observed that there was an increase in the temperature of the solutions contained in beakers A and B, whereas, in the case of beaker C, the temperature of the solution falls. Which one of the following statement(s) is (are) correct?In beakers A and B, the exothermic process has occurred.In beakers A and B, the endothermic process has occurred.In beaker C exothermic process has occurred.In beaker C endothermic process has occurred.(a) (i) only(b) (ii) only(c) (i) and (iv)(d) (ii) and (iii)
- Three beakers labelled as A, B, and C each containing 25 mL of water were taken. A small amount of NaOH, and. CuSO4 and NaCl were added to the beakers A, B, and C, respectively. It was observed that there was an increase in the temperature of the solutions contained in beakers A and B whereas, in the case of beaker C, the temperature of the solution falls. Which one of the following statements is/are correct?In beakers A and B, an exothermic process has occurred.In beakers A and B, an endothermic process has occurred.In beaker C, the exothermic process has occurred.In beaker C, an endothermic process has occurred.Only IOnly III and IVII and III
- An electric bulb is connected to a cell through a switch as shown in figure. When the switch is brought in ‘ON’ position, the bulb does not glow. What could be the possible reason/s for it? Mention any two of them."
- A student prepared 20% sodium hydroxide solution in a beaker containing water. The observations noted by him are given below.I. Sodium hydroxide is in the form of pellets.II. It dissolves in water readily.III. The beaker appears cold when touched from outside.IV. Red litmus paper turns blue when dipped into the solution. The correct observations are:(a) I, II, and III(b) II, III and IV(c) III, IV and I(d) I, II and IV
- Blue litmus solution is added to two test tubes A and B containing dilute HC1 and NaOH solution respectively. In which test tube a colour change will be observed? State the colour change and give its reason.
- (a) State the various characteristics of chemical reactions.(b) State one characteristics each of the chemical reaction which takes place when:(i) dilute hydrochloric acid is added to sodium carbonate (ii) lemon juice is added gradually to potassium permanganate solution (iii) dilute sulphuric acid is added to barium chloride solution (iv) quicklime is treated with water(v) wax is burned in the form of a candle
- Mention with reason the colour changes observed when :(i) silver chloride is exposed to sunlight.(ii) copper powder is strongly heated in the presence of oxygen.(iii) a piece of zinc is dropped in copper sulphate solution.
- The teacher instructed three students ‘A’, ‘B’ and ‘C’ respectively to prepare a 50% (mass by volume) solution of sodium hydroxide (NaOH). ‘A’ dissolved 50g of NaOH in 100 mL of water, ‘B’ dissolved 50g of NaOH in 100g of water while ‘C’ dissolved 50g of NaOH in water to make 100 mL of solution. Which one of them has made the desired solution and why?
- What is the effect of the following on an animal cell:(i) Hypotonic solution (ii) Isotonic solution (iii) Hypertonic solution?
Kickstart Your Career
Get certified by completing the course
Get Started