Why a polystyrene cup is used instead of a glass beaker to find out heat of neutralization?

1 Answer

Answer :

Ans: A polystyrene cup acts as an insulator therefore it will not allow heat to exchange between reaction mixture and its surroundings and enthalpy of reaction doesn’t change . On the other hand glass can easily transfer and exchange heat bringing change in enthalpy of reaction.

Related questions

Description : What is the value of heat of neutralization when strong acid and base react?

Last Answer : Ans: The heat of neutralization is -57.32 kJ, when strong acid and base react.

Description : On which factors heat content of a system depends?

Last Answer : Ans: Heat content (enthalpy of a reaction depends upon two factors I. Physical state of reactants II. Temperature

Description : Why in endothermic reaction we have to provide heat to the system?

Last Answer : Ans: In endothermic reactions the energy of the products is more than that of the reactants, so in order to form the product we have to provide energy to the system.

Description : What are spectator ions?

Last Answer : During a neutralization reaction anion of acid and cation of base don’t take part in the reaction and remain in the solution .These ions are called spectater ions.

Description : Why enthalpy of water in liquid state (25 C) is less than the enthalpy of steam (100 C)?

Last Answer : Ans: Enthalpy of water in liquid state is less than steam because the steam is at high temperature i.e;100 C, whereas that of liquid water is 25 C.

Description : What is the effect of endothermic and exothermic reactions on temperature of surroundings.

Last Answer : Ans: In endothermic reactions heat is absorbed from the surroundings resulting in decrease of temperature. Whereas heat is evolved in surrounding during exothermic reaction so temperature of surroundings increases.

Description : Define thermochemistry?

Last Answer : “The branch of chemistry in which we study the heat changes during chemical reactions is called ThermoChemistry”.

Description : Take a 250 mL beaker/glass tumbler. Fill half of it with water. Now carefully cut a small piece of sodium metal. Dry it using filter paper and wrap it in a small piece of cotton. Put the sodium piece wrapped in cotton into the beaker. Observe carefully. -Science

Last Answer : On touching the beaker, it was felt hot. The solution turns the red litmus paper to blue which shows it is basic in nature. Blue litmus paper do not show any colour change with the solution.

Description : Calculate the index of refraction of a liquid from the following into glass: (a) Reading for the bottom of an empty beaker: 11.324 cm (b) Reading for

Last Answer : Calculate the index of refraction of a liquid from the following into glass: (a) Reading for the ... level of the liquid in the beaker: 12.895cm

Description : If an ordinary glass tube and a glass capillary tube are 'both clipped in a beaker of water, water rises in – (1) both (2) only the glass tube (3) only the capillary tube (4) neither

Last Answer : (1) both Explanation: The rise or fall of liquid due to capillarity in a beaker of water depends upon the radius of the bore of the tube (s) which is/are dipped into it. The narrower the bore of ... in the tube. So in this case, water will rise in both the glass tube and the glass capillary tube.

Description : If an ordinary glass tube and a glass capillary tube are both dipped in a beaker of water, water rises in (1) both (2) only the glass tube (3) only the capillary tube (4) neither

Last Answer : both

Description : Where do the water in the beaker get its heat energy from?

Last Answer : the fire

Description : To ensure that the heat from a burner is spread evenly across the bottom of a beaker, one should use a _______.?

Last Answer : i don’t know

Description : Describe an activity to observe what happens when quick lime is added to water taken in a beaker. State two important observations and name the type of reaction taking place. -Chemistry

Last Answer : Answer. Aim: To observe what happens when quicklime is added to water taken in a beaker. Materials Required:- Quicklime (calcium oxide), water, beaker.Procedure: 1. Take 5 g of calcium oxide in a ... example for each of decomposion reaction carried out with help of (i) Electricity (ii) Heat (iii)

Description : 15 mL of water and 10 mL of sulphuric acid are to be mixed in a beaker (i) State the method that should be followed with reason. (ii)What is this process called? -Chemistry

Last Answer : (i) The acid is to be added slowly in water to prevent the mixture to be splashed. The reaction is highly exothermic, therefore, constant cooling should be done. (ii)The process is called dilution.

Description : A beaker of ethyl alcohol is marked 188 proof. What percentage of the liquid is ethyl alcohol?

Last Answer : ANSWER: 94%

Description : _______ is the process in which acids and bases react to form salts and water. (1) Neutralization (2) Electrolysis (3) Distillation (4) Hydrolysis

Last Answer : (1) Neutralization Explanation: Neutralization is a process when acids and bases react to form salt and water.

Description : 0.257g of organic substance was heated with conc. sulphuric acid and then distilled with excess of strong alkali .the ammonia gas evolved was absorbed in 50ml of .1M HCl which required 23.2ml of c for neutralization at the end of the process. Determine the % of nitrogen in the compound ?

Last Answer : A. Vol of 0 .1M HCl taken = 50ml Vol of .1MNaOH used for neutralization of unused acid=23.2ml Now, 23.2 ml of .1MNaOH =23.2ml of .1MHCl Vol of .1MHCl unused=23.2ml Vol of .1MHCl required ... NH3 solution contain nitrogen = 14*26.8/10*1000 Percentage of Nitrogen=14*26.8*100/10*1000*.257 =14.6%

Description : (i)What happens to the internal energy of the system. (a) if work is done by the system. (b)Work is done on the system. (ii) Why enthalpy of neutralization of strong acid and base is consant?

Last Answer : Ans. (i).(a)ΔU Decreases. (ΔU = q - w) (b)ΔU increases. (ΔU = q + w) (ii) Strong acids and bases dissociate completely into ions in aqueous solution and form 1 mole of water.

Description : What is the process by which an atom gains electrons? w) Reduction x) Neutralization y) Electrolysis z) Oxidation

Last Answer : ANSWER: W -- REDUCTION

Description : The hydrolysis of a fat using a solution of a strong hydroxide is called: w) neutralization x) esterification y) saponification z) condensation

Last Answer : ANSWER: Y -- SAPONIFICATION

Description : When an aldehyde is heated with Fehling's solution, the aldehyde undergoes one of the following processes. Does it undergo: w) neutralization x) oxidation y) reduction z) esterification

Last Answer : ANSWER: X -- OXIDATION

Description : Which of the following is used as no coating for Cooking utensils? (1) Perspex (2) Styrofoam (3) Polystyrene (4) (4)Teflon

Last Answer : (4)Teflon Explanation: The non-stick coating used mainly for coating cooking utensils is made using PTFE (polytetrafluoroethylene) that is also known by the name Teflon. Teflon is an inert polymer ... containing substances wet it and it has one of the lowest coefficients of friction of any solid.

Description : The name of plastic polymer from which combs, toys, bowls etc., can be made, is (1) Polyurethane (2) Polystyrene (3) Metallic polysulphides (4) Teflon

Last Answer : (2) Polystyrene Explanation: Polystyrene is an synthetic aromatic polymer made from the monomer styrene, a liquid petrochemical. It is one of the most widely used plastics. Uses include protective ... containers (such as "clamshells"), lids, bottles, trays, tumblers, and disposable cutlery.

Description : Which one among the following polymers is used for making bullet-proof material? (1) Polyvinyl chloride (2) Polystyrene (3) Polyethylene (4) Polyamide

Last Answer : (3) Polyethylene Explanation: A bullet-proof material is made of polyethylene. It is a higher grade of the plastic found in Tupperware.

Description : Write the structure of monomer of polystyrene.

Last Answer : Ans: Styrene. Ar— CH=CH2 

Description : Write the structure of monomer of Polystyrene? 

Last Answer : Ans: Ar CH = CH2 

Description : Write the monomer of Polystyrene? 

Last Answer : Ans: Styrene. 

Description : Which of the following is used as non-stick coating for cooking utensils? (1) Perspex (2)Styrofoam (3) Polystyrene (4)Teflon

Last Answer : Teflon

Description : The name of plastic polymer from which combs, toys, bowls etc., can be made, is (1) Polyurethane (2) Polystyrene (3) Metallic polysulphides (4) Teflon

Last Answer : Polystyrene

Description : How can I make a Beaker Muppet costume for next Halloween?

Last Answer : Follow these instructions to make a beaker muppet costume

Description : While determining the refractive index of a liquid experimentally, the microscope was focussed at the bottom of a beaker, when its reading was 3.965 c

Last Answer : While determining the refractive index of a liquid experimentally, the microscope was focussed at the ... . Find the refractive index of the liquid.

Description : In Fig. a plane mirror lies at a height h above the bottom of a beaker containingwater (refractive index `mu`) upto a height f. Find the position of t

Last Answer : In Fig. a plane mirror lies at a height h above the bottom of a beaker containingwater (refractive index ... f. Find the position of the image of the

Description : When heating a beaker of H20 on a hot plate there are 3 types of energy conversions?

Last Answer : Need answer

Description : What is the hazard for beaker?

Last Answer : Need answer

Description : If there is 50 ml of water in a beaker then what is the mass?

Last Answer : 50 gm

Description : What is a stand and mat used to hold a beaker or flask over a Bunsen burner?

Last Answer : Need answer

Description : If a student dissolves powdered sugar in a water in a beaker the student then places a strip of silver in the beaker what is the solute in this solution?

Last Answer : Sugar is the solute.

Description : When a cube of ice floating on water in a beaker melts, the level of water in the beaker (a) rises (b) falls (c) remains the same (d) first rises and then falls

Last Answer : Ans:(c)

Description : A capillary tube is kept vertical in a beaker containing liquid. The height to which the liquid rises by capillary action is increased if (a) The radius of the capillary is large (b) The radius of the ... small (c) The density of the liquid is large (d) The surface tension of the liquid is small

Last Answer : Ans:(b)

Description : A piece of ice is floating in water kept in a beaker. When all the ice melts the level of water will - (1) first rise and then fall (2) fall (3) remain the same (4) rise

Last Answer : (3) remain the same Explanation: The submerged portion of the ice on melting shrinks a little in volume. So the level of water goes down a little. But this is just made up by the water added by the melting of upper portion.

Description : When black copper oxide placed in a beaker is treated with dilute HCl, its colour changes to......... a) Whiteb) Red c) Blue-green d) No change

Last Answer : c) Blue-green

Description : Water contained in a beaker can be made to boil by passing steam through it  (a) at atmospheric pressure  (b) at a pressure below the firuosphejric pressure  (c) at a pressure greater than atmospheric pressure  (d) any pressure  (e) not possible.

Last Answer : Answer : c

Description : Products of neutralization reaction are always -Science-7

Last Answer : Products of neutralization reaction are always a salt and water.

Description : what is the neutralization?

Last Answer : Neutralization is the reaction between an acid and a base, the products being a salt and water.

Description : Which of the following best describes a neutralization reactions?

Last Answer : Answer this question… Which of the following best describes a neutralization reaction? A. Acid + base H+ + OH- B. Acid + base salt + water C. Acid + base metal + nonmetal D. Acid + base H2O + H3O+

Description : The absolute enthalpy of neutralization of the reaction, `MgO(s)+2HCl(aq.)+H_(2)O(l)` will be

Last Answer : The absolute enthalpy of neutralization of the reaction, `MgO(s)+2HCl(aq.)+H_(2)O(l)` will be A. `57.33" kj ... )` D. Less than `=57.33" kj mol"^(-1)`

Description : `{:("column I","column II"),("(A)"4.1gH_(2)SO_(3),"(p) 200 mL of 0.5 N base is used for complete neutralization"),("(B)" 4.9 g H_(3)PO_(4),"(q) 200 mi

Last Answer : `{:("column I","column II"),("(A)"4.1gH_(2)SO_(3),"(p) 200 mL of 0.5 N base is used for ... Na_(2)CO_(3),"(s)May react with an oxidising agent"):}`

Description : What salt results from the neutralization of phosphoric acid with potassium hydroxide?

Last Answer : Feel Free to Answer