How much heat is necessary to supply 2 kilograms of aluminum to raise its temperature by 20 ° C?
Answer:
36000J
Explanation:
Given parameters:
Mass of aluminum = 2kg = 2000g
Temperature rise = 20°C
Unknown:
Amount of heat needed for the temperature change = ?
Solution:
The amount of heat needed to cause this temperature rise is given as;
H = m c (T₂ - T₁)
H is the amount of heat
m is the mass
c is the specific heat of aluminum = 0.9J/g°C
Insert the parameters and solve;
H = 2000 x 0.9 x 20 = 36000J
Answer:
I like some animes but it just really is up to you like im happy that anime was created so for me its a good thing
Explanation:
The statement of the combined gas law for a fixed amount of gas is,
PV/T = constant
Here, the units of pressure and volume must be consistent and the temperature must be the absolute temperature (Kelvin or Rankine).
0.65 atm is equivalent to 494 mmHg
Using the equation:
(755 x 500) / (27 + 273) = (494 x V) / (-33 + 273)
V = 3396 ml = 3.4 liters
Answer:
D
Explanation:
There are principally three states of matter. These are the solid, liquid and gaseous states. The gaseous state has the highest degree of disorderliness as gas particles can move randomly while the solid state has the highest level of compactness.
Hence, we need to be adequately fed with information as regards the phase change to know if entropy has decreased or increased.
A. is wrong
Evaporation is a change of state to the gaseous state meaning there is an increased entropy.
B. is wrong
Sublimation is a change of state which means a solid substance like iodine or naphthalene changes its state directly to the gaseous state. There is an increased entropy here too.
C is wrong
Melting of ice means going from ice block to liquid water. This is synonymous to going from the solid state to the liquid state which is an increased entropy
D is correct
Condensation involves going from the gaseous state to the liquid state. This means going from a less ordered state to a more ordered state. This is accompanied by an entropy decrease.
E is wrong
While there are some processes that increase entropy, we also have some process that decrease entropy.
Density is a property of a material which describes the mass of a material per unit volume. Density is said to be slightly dependent on temperature. We look at the density of water at different temperatures:
<span>
100 </span>°C: 958.4 kg/m^360 °C: 983.2 kg/m^320 <span>°C</span>: 998.2 kg/m^3
Therefore, warm water has a lower density than water in colder temperature.
