Answer:
Thus, random error primarily affects precision. Typically, random error affects the last significant digit of a measurement. The main reasons for random error are limitations of instruments, environmental factors, and slight variations in procedure.
Explanation:
2Cu(s) + O2(g) --> 2CuO(s)
Some of the liquid surface particles may gain enough KE to escape into the space above the liquid - evaporate. ... The kinetic molecular theory states that all matter is made up tiny constantly moving particles and in a solid they are packed tightly. (Only answered part of the question, sorry bro)
Answer:
Explanation:
Solubility of many solid in a solvent increases with increase in temperature. Increase in temperature increases kinetic energy of the solute, increasing collision and weakens the intermolecular force within the solute. This makes the solute dissolve faster in their solvents.
During recrystallization, more solutes are added to the solvent at higher temperature so that a supersaturated solution is produced on cooling. As the solution cools the over saturated solute begins to precipitate out of the solution.
Recrystallization is a form of purification if solid, as the crystalline solids continue to precipitate it reject impurities are comes out as a purer solid
I think A is correct:
deltaH=(Enthalpie of reactents)-(Enthalpie of products)=110.525+285.5-393.5=2.525~2.825
