Answer:
Explanation:To convert from cal/(g*C) to J/(kg*K), we just need to find a conversion factor for specific heat. There is really no mathematical way to do this other than to look in a physics or chemistry book and find a conversion factor. After doing this, you will see that 1 cal/(g*C) is equal to 4,186 J/(kg*K).
To find the specific heat of a material, first look at the units. There is energy per unit mass per unit temperature. So if we are given an amount of energy appllied to an object, its mass and how much the temperature of the object rises, we can calculate its specifc heat by dividing the energy by both the mass and the temperature, but don't forget to keep the units as they are:
Specific heat of the metal = (95 cal)/(10 K * 700g) = 0.014 cal/(g*K)
To find how much energy it requires to melt 250 grams of ice, we will need what is called the Latent Heat of Melting for ice. This is the amount of heat required to change unit mass of a solid into unit mass of a liquid at a constant temperature. Again, using a reference, the latent heat of melting for ice is found to be 334 kJ/kg. So the energy required to melt one kg of ice is 334 kJ. The amount of energy required to melt 0.250 kg of ice is then:
334 * 0.250 = 83.5 kJ
Answer:
M
Explanation:
Henry's law relational the partial pressure and the concentration of a gas, which is its solubility. So, at the sea level, the total pressure of the air is 1 atm, and the partial pressure of O2 is 0.21 atm. So 21% of the air is O2.
Partial pressure = Henry's constant x molar concentration
0.21 = Hx1.38x
H = 
H = 152.17 atm/M
For a pressure of 665 torr, knowing that 1 atm = 760 torr, so 665 tor = 0.875 atm, the ar concentration is the same, so 21% is O2, and the partial pressure of O2 must be:
P = 0.21*0.875 = 0.1837 atm
Then, the molar concentration [O2], will be:
P = Hx[O2]
0.1837 = 152.17x[O2]
[O2] = 0.1837/15.17
[O2] = M
Answer:
An acid is a substance that donates hydrogen ions. Because of this, when an acid is dissolved in water, the balance between hydrogen ions and hydroxide ions is shifted. Now there are more hydrogen ions than hydroxide ions in the solution. This kind of solution is acidic.
Explanation:
Transparency (also called pellucidity or diaphaneity) in the field of optics is the physical property of allowing light to pass through the material without significant light dispersion.
Answer:
(a) I⁻ (charge 1-)
(b) Sr²⁺ (charge 2+)
(c) K⁺ (charge 1+)
(d) N³⁻ (charge 3-)
(e) S²⁻ (charge 2-)
(f) In³⁺ (charge 3+)
Explanation:
To predict the charge on a monoatomic ion we need to consider the octet rule: atoms will gain, lose or share electrons to complete their valence shell with 8 electrons.
(a) |
I has 7 valence electrons so it gains 1 electron to form I⁻ (charge 1-).
(b) Sr
Sr has 2 valence electrons so it loses 2 electrons to form Sr²⁺ (charge 2+).
(c) K
K has 1 valence electron so it loses 1 electron to form K⁺ (charge 1+).
(d) N
N has 5 valence electrons so it gains 3 electrons to form N³⁻ (charge 3-).
(e) S
S has 6 valence electrons so it gains 2 electrons to form S²⁻ (charge 2-).
(f) In
In has 3 valence electrons so it loses 3 electrons to form In³⁺ (charge 3+).
