Answer:
The solution to the given problem is done below.
Explanation:
a)
i) =( 0.002 μg / L )( 1mg / 1000 μg )( 1L / kg )( 1000 mil / 1 billion) = 0.002 ppb
ii) =( 0.002 μg / L )( 1mg / 1000 μg )( 1L / kg )( 1,000,000 mil / 1 trillion) = 2 ppt
iii) =( 0.002 μg / L )( 1 mole / 540g ) = 3.7 x
μM.
b)
i) =( 0.002 μg / g ) = 0.002 ppm
ii) In solids, ppb = μg/kg
=( 0.002 μg / g )( 1000 mil/ 1 billion) = 2 ppb
This question can be simply solved by using heat formula,
Q = mCΔT
Q = heat energy (J)
m = Mass (kg)
C = Specific heat capacity (J / kg K)
ΔT = Temperature change (K)
when water freezes, it produces ice at 0°C (273 K)
hence the temperature change is 25 K (298 K - 273 K)
C for water is 4186 J / kg K or 4.186 J / g K
By applying the equation,
Q = 456 g x 4.186 J / g K x 25 K
= 47720.4 J
= 47.72 kJ
hence 47.72 kJ of heat energy should be removed.
Answer:
1 is the answer
Explanation:
The ionic formula for Lithium Oxide is Li2O . Lithium is an Alkali Metal in the first column of the periodic table. This means that lithium has 1 valence electron it readily gives away in order to seek the stability of the octet.
Answer:
B : Their constant motion
C: Ideal gas law
Explanation:
Question 1:
Gas particles collides with the walls of their containers due to their constant motion.
Gases moves randomly and haphazardly in all direction and they collide with themselves and the walls of their container.
The kinetic theory of gases provides a better oversight into this;
- The pressure of the gases is caused by the frequent collision between the gases and their container.
- The molecules of gases collides with one another and with walls of their container elastically without any loss of kinetic energy.
Based on this premise, we can clearly decipher that gas particles collides with the walls of their containers because they are always in constant motion
Question 2:
Given parameters:
Mass of the Helium gas = 5g
Volume of gas = 10mL
Pressure on gas = 20mmHg
Unknown:
Appropriate gas law to solve this problem = ?
Solution:
The ideal gas law would be the perfect plug to derive the unknown temperature.
This gas law is a derivative of the of three gas laws which are;
- Boyle's law
- Charles's law
- Avogadro's law
The law is written as:
PV = nRT
P is the pressure
V is the volume
R is the gas constant
n is the number of moles
T is the unknown temperature in this problem
- The ideal gas law is used to find any of the variables (P, V, n and T)
the number of moles is;
number of moles = ![\frac{mass}{molar mass}](https://tex.z-dn.net/?f=%5Cfrac%7Bmass%7D%7Bmolar%20mass%7D)
Answer:
c. 0.033T - 2.6 °C
Explanation:
Hello,
In this case, we should conclude that the energy lost by the water is gained by the ice to get melted, thus, we can write them in terms of melting and cooling enthalpies:
![\Delta H_{ice,melting}=-\Delta H_{water,cooling}](https://tex.z-dn.net/?f=%5CDelta%20H_%7Bice%2Cmelting%7D%3D-%5CDelta%20H_%7Bwater%2Ccooling%7D)
First term includes melting enthalpy of ice that is 333.89 J/g and the second one specific heat of water that is 4.18 J/g°C, therefore, we obtain:
![8.4g*333.89\frac{J}{g}=-260g*4.18\frac{J}{g\°C}(T_2-T_1) \\\\(T_2-T_1) =-\frac{8.4g*333.89\frac{J}{g}}{260g*4.18\frac{J}{g\°C}} \\\\(T_2-T_1)=-2.6\°C](https://tex.z-dn.net/?f=8.4g%2A333.89%5Cfrac%7BJ%7D%7Bg%7D%3D-260g%2A4.18%5Cfrac%7BJ%7D%7Bg%5C%C2%B0C%7D%28T_2-T_1%29%20%20%5C%5C%5C%5C%28T_2-T_1%29%20%3D-%5Cfrac%7B8.4g%2A333.89%5Cfrac%7BJ%7D%7Bg%7D%7D%7B260g%2A4.18%5Cfrac%7BJ%7D%7Bg%5C%C2%B0C%7D%7D%20%5C%5C%5C%5C%28T_2-T_1%29%3D-2.6%5C%C2%B0C)
Thus, answer should be c. 0.033T - 2.6 °C since it includes the temperature decrease of water due to the undergoing cooling.
Best regards.