To solve this we use the
equation,
<span> M1V1 = M2V2</span>
<span> where M1 is the
concentration of the stock solution, V1 is the volume of the stock solution, M2
is the concentration of the new solution and V2 is its volume.</span>
<span>2.0 M x V1 = 0.50 M x 200 mL</span>
<span>V1 = 50 mL needed</span>
In an exothermic reaction, heat is produced along with products. But in endothermic reaction, heat is absorbed. If the number of products is less than the sum of the enthalpies of the reactants, the reaction will be exothermic. If the number of products is more than the sum of the enthalpies of the reactants, the reaction is endothermic.
Answer is: <span>the volume of water after the solid is added</span> is 4.5 ml.
d(gold) = 8.0 g/cm³; density of gold.
m(gold) = 4 g; mass of gold.
V(gold) = m(gold) ÷ d(gold); volume of gold.
V(gold) = 4 g ÷ 8 g/cm³.
V(gold) = 0.5 cm³ = 0.5 ml.
V(water) = 4.00 ml = 4.00 cm³.
V(flask) = V(gold) + V(water).
V(flask) = 0.5 cm³ + 4 cm³.V = 4.5 cm³.
one mole of P weights about 31 grams
in one mole there are 6.022*10^23 atoms
we use the rule of threes
6.022*10^23atoms......weight..........31 grams
3.45*10^23 atoms.........weight...........x grams
x=(3.45*10^23*31)/6.022*10^23
x=106.95/6.022=<u><em>17.76 grams</em></u>
