Answer:
2) Copper (II) Chloride
Explanation:
A precipitate will form if the resulting compound is insoluble in water. For example, a silver nitrate solution (AgNO3) is mixed with a solution of magnesium bromide (MgBr2).
As the concrete has cement, gravel, crushed rocks, sand, and water of different physical state and can be separated by physical methods hence it should be called as a mixture.
As the components have significant physical boundaries which clearly identify their presence, the mixture is heterogeneous and not homogeneous.
Thus this is a concrete is a heterogeneous mixture of cement, gravel, crushed rocks, sand, and water
Reaction:
<span>HCl + NaOH ---> NaCl + H2O
</span><span>1 mole of HCl = 36,5 g
</span><span>1 mole of NaOH = 40g
</span><span>so, according to the reaction:
</span><span>1 mol HCl = 1 mol NaOH
</span>so, we need > 36,5 g HCl (<u>hydrochloric acid</u><span>)
</span><u>
answer: 36,5 g HCl (hydrochloric acid)
</u><span> ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
</span><span>next question.
</span><span>
1 mole of NaCl = 58,5 g
</span><span>1 mole of H2O = 18g
</span>
so, according to the reaction:
1 mole of HCl (36,5 g) <span>----------------- - 1 mole of NaCl (58,5 g)
</span><span>(the same for NaOH)
i
</span>1 mole of HCl<span> (36,5 g) ------------------ 1 mole of H2O (18 g)
</span>(the same for NaOH)
<span>so, this reaction is stechiometric
</span><u>
answer: 58,5 g NaCl i 18g H2O</u>
n(2Fe2O3)=10g/319.374amu=0.03mol
n(4Fe+3O2)=0.03 mol
m(4Fe+2O2)=Mn=319.374×0.03=9.58=10
