A `6.85g` sample of the hydrated`Sr(OH)_2.x H_2O` is dried in an oven to given `3.13g` of anhydrous `sr(OH)_2.` What is the value of `x?` (Atomic masses : `Sr=87.60.O=16.0,H=1.0)`

The hydrate salt Na_2 CO_3.xH_2O undergoes 63% loss in mass on heating and becomes anhydrous. The value of x is :

The enthalpy of the reaction forming PbO according to the following equation is 438 kJ. What heat energy (kJ) is released in formation of 22.3 g PbO(s)? (Atomic masses : Pb = 207, O = 16.0) 2Pb(s) +O_(2)(g)rarr2PbO(s)

Find the number of molecules in 1.8 g of H_2O .

W is the mass of iron (in g) which will be converted into Fe_(3)O_(4) by the action of 18 g of steam on it . What is the value of W/7 ? Fe+H_(2)O to Fe_(3)O_(4)+H_(2)

44g of a sample on complete combustion given 88g CO_2 and 36g of H_2 O. The molecular formula of the compound may be :

The formula of an acid is HXO_2 . The mass of 0.0242 moles of the acid is 1.657g . What is the atomic mass of X ?

Calculate the number of oxygen atoms in 0.10 mole of Na_2CO_3* 10H_2O .

What is the pH of a solution in which 10.0 mL of 0.010 M Sr(OH)_(2) is added to 10.0 mL of 0.010 M HCl?

An analysis of the rock shows that the relative number of Sr^(87) and Rb^(87) (t_(1//2)=4.7 xx10^(10) year) atoms is 0.05 . What is the age of the rock? Assume all the Sr^(87) have been formed from Rb^(87) only a) 7.26 xx10^(9) year b) 1.43 xx 10^(9) year c) 3.28 xx 10^(9) year d) 4.32 xx10^(8) year

Calculate the normality of solution containing 31.5g of hydrated oxalic acid C2H2O4. 2H2O in 1250 ml of solution?