Explain why quartz, sio2(s), does not spontaneously decompose into silicon and oxygen at 25 °c in the reaction: sio2 (s) → si(s) + o2(g) even though the standard entropy change of the reaction is large and positive (i. e. as° = 182.02 jk 'mol-'). + +

ΔH > O and ΔH > TΔS

Explanation:

When a reaction is non-spontaneous even though the standard entropy change of the reaction is large and positive the reason is the reaction is highly endothermic and dominates the term TΔS in the standard Gibbs free energy expression:

ΔG = ΔH-TΔS

Remember that for an endothermic  reaction to be spontaneous ΔG < 0 and this can occur only if the term TΔS is greater than ΔH. This is not the case for quartz which requires a good quantity of energy to overcome its crystaline 3D lattice in which  the oxygen are shared between 2 silicon atoms.

answer: any goods being imported from another country may be subject to issued by the federal government are tariffs

explanation:  

tariffs are a tax on anything that are imported from abroad. government use them to protect and boost their local industries and the thought is that they encourage consumers to buy local instead of importing and they will hope will protect jobs and economy in the country that implements them  

the dissociation of nickel hydroxide is follows:

the concentration of hydroxide ion is

the equilibrium constant value of nickel hydroxide is = 6.1 * 10^-^1^6 and thus equilibrium equation can be written as:

thus, concentration of ni is 0.23 * 10^-^4 mol /l