On adding dilute HCI to copper oxide powder, the solution formed is blue- green.

Iron nails become reddish brown in colour and solution becomes green in colour.

The oxide of the element is basic as it turns red litmus blue .This means that the element is a metal (M).

Solution: Total number of outcomes = 24 P (Green) = 2/3 If number of green balls is G then; G/24 = 2/3 or, G = (24*2)/3 = 16 Hence, number of blue balls = 24 –...

(a) When dilute sulphuric acid is poured on a copper plate, there will be evolution of hydrogen gas along with the formation of blue color crystals of copper sulphate.  CuSO4 +...

2Cu(NO3) 2 (s)  ------>   Heat   2CuO(s) + O2(g)  +  4NO2(g) CoPPer(II) nitrate CoPPer oxide 'X'is nitrogen dioxide gas.

(c) both physical change. 

(a) 2Cu(NO3)2 → 2CuO+ 4NO2+O2 (b) The brown gas 'X' has to be nitrogen dioxide. (c) This type of reaction falls under the category of Decomposition reactions. (d) The pH of the aqueous...

(D) It smells like vinegar and turns blue litmus red.

d. both (a) and (c) is correct

(e) If the drawn ball is neither red nor green, then it must be blue, which can be picked in 7C1 = 7 ways. One ball can be picked from...