Fill in the blanks.
a) In a chemical reaction, the sum of the masses of the reactants and products remains unchanged. This is called law of conservation of mass.
b) A groupof atoms carrying a fixed charge on them is called polyatomic ion.
The formula unit masss of `Ca_(3)(PO_(4))_(2)` is 310g.
d) Formula of sodium carbonate is .............. and that of ammonium sulphate is.............

Fill in the blanks (a) In a chemical reaction, the sum of the masses of the reactants and products remains unchanged. This is called ————. (b) A group of atoms carrying a fixed charge on them is called ————. (c) The formula unit mass of Ca3 (PO4)2 is ————. (d) Formula of sodium carbonate is ———— and that of ammonium sulphate is ————

Fill in the following blanks with suitable words : (a) In water , the proportion of oxygen and hydrogen is "…………." by mass. (b) In a chemical reaction, the sum of the masses of reactants and the products remains unchanged. This is called "..........." .

In a chemical reaction, 10.6g of sodium carbonate reacted with 12g of ethanoic acid. The products obtained were 4.4g of carbon dioxide, 16.4 of sodium ethanoate and 1.8g of water. (a)Write a word equation, clearly showing the reactants and products as given above. (b)Also show that this data is in aggrement with the law of conservations of mass.

Fill in the following blanks with suitable words: (a) The form of carbon which is know as black lead is …….. (b) The form of carbon which is used as a lubricant at high temperature is….. (c ) compounds of carbon with hydrogen alone are called ....... (d) C_(n)H_(2n) is the general foumula of .................... hydrocarbons. (e ) Hydrocarbons haveing the general formula C_(n)H_(2n-2) are called ................... (f) Ethyne and ethyne are examples of ....................hydrocatbons. (g) Ethyne has .................. carbon hydrogen single bonds. (h) carbon compounds have usually ................. melting p[oints and boiling points beacuse they are.................. in nature. (i) The prperty of carbon atoms to form along chains in compounds is called........... (J) The general formaula C_(n)H_(2n) for cycloalkanes is the same as that of ................ (k) The IUPAC name of ethylene is .................... (l) The IUPAC name of acetyleneis ........................

Ravi was performing some experiements related to the laws of chemical combination in the science laboratory under the guidance of his chemistry teacher Mr. John. Ravi found that when he burned 1 gram of hydrogen gas in 8 grams of oxygen gas in a closed vessel, he obtained 9 grams of water. He repeated this experiment many times but obtained the same results every time (a) Write a balanced chemical equation for the reaction between hydrogen and oxygen to form water. Also write the names of all the substances involved below their formulae in the equation (b) What are the reactants and products in the above reaction ? (c) Which law of chemical combination is illustrated by the fact that when Ravi burned 1g of hydrogen in 8g of oxygen, he obtained 9g of water ? (d) What mass of water will be obtained if 1g of hydrogen is burned in 10g of oxygen ? Which law of chemical combination will govern your answer ? (e) What values are displayed by Ravi in this episode ?

Fil in the blanks a. The mass of 1 molecule of water (H_(2) O) is ……… b. The number of molecules in 16 g of sulphur dioxide (SO_(2)) are ………. c. The weight of one mole of sodium carbonate (Na_(2) CO_(3)) is…………….. d. Moles and g equivalent in 196 g of Ca (OH)_(2) are ...... and ....... e. Moles and g equivalent in 196 g of H_(3) PO_(4) are ............. and ............ f. g atoms in 62 g of P_(4) are ....... f. g atoms in 24 g of magnesium are...........

Fil in the blanks a. The mass of 1 molecule of water (H_(2) O) is ……… b. The number of molecules in 16 g of sulphur dioxide (SO_(2)) are ………. c. The weight of one mole of sodium carbonate (Na_(2) CO_(3)) is…………….. d. Moles and g equivalent in 196 g of Ca (OH)_(2) are ...... and ....... e. Moles and g equivalent in 196 g of H_(3) PO_(4) are ............. and ............ f. g atoms in 62 g of P_(4) are ....... f. g atoms in 24 g of magnesium are...........

Equivalent Mass The eqivalent mass of a substance is defined as the number of parts by mass of it which combine with or displace 1.0078 parts by mass of hydrogen, 8 parts by mass of oxygen and 35.5 parts by mass of chlorine. The equivalent mass of a substance expressed in grams is called gram equivalent mass. The equivalent mass of a substance is not constant. It depends upon the reaction in which the substance is participating. A compound may have different equivalent mass in different chemical reactions and under different experimental conditions. (a) Equivalent mass of an acid It is the mass of an acid in grams which contains 1.0078 g of replaceable H^(+) ions or it is mass of acid which contains one mole of replaceable H^(+) ions. It may be calculated as : Equivalent mass of acid= ("Molecular mass of acid")/("Basicityof acid ") Basicity of acid = Number of replaceable hydrogen atoms present in one molecule of acid (b) Equivalent mass of a base It is the mass of the base which contains one mole of replaceable OH^(-) ions in molecules. Equivalent mass of base= ("Molecular mass of acid ")/("Acidity of acid") Acidity of base= Number of replaceable OH^(-) ions present in one molecule of the base Equivalent mass of an oxidising agent (a) Electron concept: Equivalent mass of oxidising agent = ("Molecular mass of oxidising agent")/("Number of electrons gained by one molecule") (b) Oxidation number concept: Equivalent mass of oxidising agent= ("Molecular mass of oxidising agent")/("Total change in oxidation number per molecule of oxidising agent") Equivalent weight of oxalic acid salt in following reaction is :( Atomic masses:O=16,C=12,K=39) H_(2)C_(2)O_(4)+Ca(OH)_(2) toCaC_(2)O_(4)+H_(2)O