Popular Class Vii X Chemistry Questions

hi all! I am not able to understand what's a Lewis acid and a Lewis base. tell me if these are Lewis acids or Lewis bases and tell me the reason. HCl, H2SO4, H3PO4, CO2, HCN. my approach: first 3 I'm not able to decide. 4th o ...

Why is the Electron affinity of chlorine greater than that of Flourine? After all, the L shell of Flourine is meant to have 8 electrons. ...

is there any liquid non metal that is a good conductor of electricity? ...

What is the difference between a combustible substance and a supporter of combustion? Thanx in advance... ...

From the metals Mg and Fe, select a different metal in each case- a) Does not react with dil hydrochloric acid b) Does not react with cold water but reacts with steam when heated.... This question came in my school chemistry ...

What do you mean by an alpha radiation? ...

Why do you think ice occupies more volume than the same mass of water? ...

this is only for ix - x which of the following salts are soluble: a) Hg2Cl2 b) CaSO4 c) (NH4)2S d)AL2(SO4)3 finding the chemistry section empty... posted the thread.. ...

I didn't understand the s,p,d,f configuration dat was mentioned in d "blue" booklet 4 class IX (Preparatory Course For batch 2010-2011) in d Periodic Table Chapter. Anyone plz xplain me dat! ...

Choose the odd one out and give reasons for your answer : Propene,Ethene,1-Butene,2-Butene I choose Ethene as the odd one out because it has no isomers,while the others have atleast 1 isomer. Was I right in my prediction? If ...

what is exactly meant by tempering and how does it occur??? ...

In a flame test,can two different colours be observed one after another?Basically, can an electron jump more than once to a higher energy state? ...

ELECTROLYSIS....... while doing electrolysis of copper(2)sulphate using copper electrodes....y does copper frm anode deposit over cathode in an uniform way...???? it may so happen that the copper ions overlap over each other. ...

If you rub a piece of gold, Au, vigorously, you can rub off 2.00 moles of gold atoms in a century. How many minutes are needed to rub off 1.50 micrograms of gold? ...

9)What type of change occurs when we boil rice? Physical Chemical Both None Your Answer b Correct Answer a Your Score-1 How is this possible? Please check the real answer. ...

What are the products formed when lead nitrate reacts with hydrochloric acid? ...

Is there any way of controlling radioactivity of an element apart from making an isotope with greater number of neutrons? If yes, what? ...

How is CO+H2 prodced? ...

A sample of chlorine is found to have 75% of 17Cl35 and 25% of 17Cl37. a. Find the average atomic mass of chlorine b. Give the number of neutrons in both the isotopes. ...

Calculate the mass of magnesium oxide obtained by burning 2.4 g of magnesium. ...

Can the anode be –vely Charged and a cathode +vely charged? Give an example if your answer is yes. ...

As far as I know, if something is mass less, it travels with speed of light and if it has mass, it cannot reach the speed of light. According to De Broglie's equation, photons do have mass but yet they travel at the speed of ...

What is the process used to make ammonia? ...

""""Organic chemistry is the study of carbon compounds (except CO, CO2, carbonates, hydrogencarbonates, carbides and cyanides) obtained from natural sources or synthesized in the laboratories."""""" so, my questn is that...y ...

i know about oxidation number but how can i define it..??????....pllzzz help... ...

Give reasons why equal volumes of nitrogen and ozone under same conditions of temperature and pressure have different number of atoms. ...

Calorific value is expressed in kJ/g right? ...

Which oxide of a metal gets reduced only by coke and not by H2 gas or Co gas? a. CuO b. PbO c. Fe2O3 d.ZnO ...

Why do we see the characteristic colour of a metal ion when a salt of that metal ion is introduced in the flame? Why is it that all metal ions do not give the flame test? ...

Although Carbon is a non-metal, but one of its allotrope, Graphite conducts electricity. Why? ...