Explain why copper 2 oxide is a base although it does not turn litmus paper to blue​

Copper (ll) oxide is a base, but it can't turn litmus paper blue because it doesn't dissociate to form H+ and OH- ions, but when it it dissolved in water then it get converted into ions and hence it changes colour of pH paper into blue.

Anhydrous acids or bases doesn't turn pH paper into red or blue because they don't form ions, when mixed with water they start showing their characteristics.

in theory, limestone is composed principally of the compound calcium carbonate - caco3, but in reality this compound is deposited in conditions involving a number of other compounds as impurities so it ends up being a mixture of many compounds.

hope this : -)

tony (lordcaos066)

the law of conservation of mass states that in a chemical reaction, the total mass of reactants is equal to the total mass of products. because atoms are only rearranged in a chemical reaction, there must be the same number of sodium atoms and chlorine atoms in both the reactants and products