What is known as 'Butter of Tin'?

Give the chemical reaction for preparing pure $CO$.

The silicate anion in the mineral kinoite is a chain of three $SiO_4$ tetrahedra that share corners with adjacent tetrahedra. The mineral also contains $Ca^{2+}$ ions,$Cu^{2+}$ ions,and water molecules in a $1 : 1 : 1$ ratio. The mineral is represented as:

Which of the following is not correct?

In the following reaction,identify the nature of the product formed by the complete hydrolysis of the underlined atom at $R.T.$:
$\underline{S}_8 + H_2O \longrightarrow$ No reaction

When graphite is heated at $300^{\circ} C$ with potassium vapour, it forms $C_8K$ compound that shows one of the following property.