Answer:
The mass of aluminum is 124.72 g
Explanation:
Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.
Sensible heat is the amount of energy that causes a change in the temperature of a substance. In other words, sensible heat is that heat that causes the temperature of an object to vary without affecting its molecular structure and therefore its physical state. Its mathematical expression is:
Q = c * m * ΔT
where Q is the heat exchanged by a body of mass m, constituted by a substance of specific heat c and where ΔT is the variation in temperature.
In this case:
- Q= 900 J
- c= 0.902
- m= ?
- ΔT= Tfinal - Tinitial= 38 °C - 30°C= 8°C as it is a temperature difference, it is indistinct if the temperature is expressed in ° C or ° K because the difference will be the same. So: ΔT= 8°C= 8 °K
Replacing:
900 J= 0.902 *m* 8 °K
900 J= 7.216 
*m
124.72 g=m
<u><em>The mass of aluminum is 124.72 g</em></u>
Answer:
Presence of water molecules
Explanation:
Temperature decreases with an increase in altitude. At sufficiently high altitudes, the air is much colder than the air on the surface of the Earth. Water vapor has a low density and is capable to rise until it gets into a medium with a significantly low temperature and pressure to condense and produce water droplets out of water vapor. Those droplets then form clouds.
Answer:
(FeSCN⁺²) = 0.11 mM
Explanation:
Fe ( NO3)3 (aq) [0.200M] + KSCN (aq) [ 0.002M] ⇒ FeSCN+2
M (Fe(NO₃)₃ = 0.200 M
V (Fe(NO₃)₃ = 10.63 mL
n (Fe(NO₃)₃ = 0.200*10.63 = 2.126 mmol
M (KSCN) = 0.00200 M
V (KSCN) = 1.42 mL
n (KSCN) = 0.00200 * 1.42 = 0.00284 mmol
Total volume = V (Fe(NO₃)₃ + V (KSCN)
= 10.63 + 1.42
= 12.05 mL
Limiting reactant = KSCN
So,
FeSCN⁺² = 0.00284 mmol
M (FeSCN⁺²) = 0.00284/12.05
= 0.000236 M
Excess reactant = (Fe(NO₃)₃
n(Fe(NO₃)₃ = 2.126 mmol - 0.00284 mmol
=2.123 mmol
For standard 2:
n (FeSCN⁺²) = 0.000236 * 4.63
=0.00109
V(standard 2) = 4.63 + 5.17
= 9.8 mL
M (FeSCN⁺²) = 0.00109/9.8
= 0.000111 M = 0.11 mM
Therefore, (FeSCN⁺²) = 0.11 mM
Answer;
A decrease in the vapor pressure of the liquid.
Dissolving a solute such as potassium hydroxide in a solvent such as water results in a decrease in the vapor pressure of the liquid.
Explanation;
The vapor pressure of a liquid is the equilibrium of a vapor above its liquid.
In other words it is the pressure of the vapor resulting from the evaporation of a liquid above a given sample of the liquid in a closed container.
The vapor pressure of a liquid in a closed container depends on the temperature.
