Answer: The density of 0.50 grams of gaseous carbon stored under 1.50 atm of pressure at a temperature of -20.0 °C is 0.867 g/L.
Explanation:
- d = m/V, where d is the density, m is the mass and V is the volume.
- We have the mass m = 0.50 g, so we must get the volume V.
- To get the volume of a gas, we apply the general gas law PV = nRT
P is the pressure in atm (P = 1.5 atm)
V is the volume in L (V = ??? L)
n is the number of moles in mole, n = m/Atomic mass, n = 0.50/12.0 = 0.416 mole.
R is the general gas constant (R = 0.082 L.atm/mol.K).
T is the temperature in K (T(K) = T(°C) + 273 = -20.0 + 273 = 253 K).
- Then, V = nRT/P = (0.416 mol)(0.082 L.atm/mol.K)(253 K) / (1.5 atm) = 0.576 L.
- Now, we can obtain the density; d = m/V = (0.50 g) / (0.576 L) = 0.867 g/L.
Answer: A. An early form of chemistry that people used to try to turn metal
into gold.
Explanation:
Alchemy is indeed an early form of chemistry in which people try to turn metal into gold.
Answer:
Explanation:
From the equation:
H2SO4(aq) + 2NaOH(aq) --> Na2SO4(aq) + 2H2O (l)
<em>1 mole of the acid (H2SO4) and 2 moles of the base (NaOH) are required for complete neutralization.</em>
mole of acid (H2SO4) present = molarity x volume
= 1 x 0.1 = 0.1 mole
Mole of base (NaOH) present = mass/molar mass
= 7/40 = 0.175 mole
<em>The ratio of acid and base should be 1:2, hence the acid is slightly excessive in this case and the base is the limiting reagent that will determine the extent of the reaction.</em>
Amount of excess acid = 0.1 - 0.175/2
= 0.0125 mole
volume of excess acid = mole/molarity
= 0.0125 x 1 = 0.0125 L
= 12.5 mL
<em>Hence, the acid (H2SO4) was in excess by 12.5 mL.</em>
