Answer:
(E) changing temperature
Explanation:
Consider the following reversible balanced reaction:
aA+bB⇋cC+dD
If we know the molar concentrations of each of the reaction species, we can find the value of Kc using the relationship:
Kc = ([C]^c * [D]^d) / ([A]^a * [B]^b)
where:
[C] and [D] are the concentrations of the products in the equilibrium; [A] and [B] reagent concentrations in equilibrium; already; b; c and d are the stoichiometric coefficients of the balanced equation. Concentrations are commonly expressed in molarity, which has units of moles / 1
There are some important things to remember when calculating Kc:
- <em>Kc is a constant for a specific reaction at a specific temperature</em>. If you change the reaction temperature, then Kc also changes
- Pure solids and liquids, including solvents, are not considered for equilibrium expression.
- The reaction must be balanced with the written coefficients as the minimum possible integer value in order to obtain the correct value of Kc
The volume of sample = 2.25(1.5)(2.25) = 7.59375 cm3
Density = mass / volume
Density = 55.75 / 7.59375 = 7.34156 g/cm3
As the density of iron is 7.86 g/cm3 instead, it is not iron
Answer:
Its pressure will be 0.54 atm at 100 K.
Explanation:
Gay-Lussac's law indicates that, as long as the volume of the container containing the gas is constant, as the temperature increases, the gas molecules move faster. Then the number of collisions with the walls increases, that is, the pressure increases. That is, the pressure of the gas is directly proportional to its temperature.
Gay-Lussac's law can be expressed mathematically as the quotient between pressure and temperature equal to a constant:

Studying two different states, an initial state 1 and a final state 2, it is satisfied:

In this case:
- P1= 1.75 atm
- T1= 50 °C= 323 K (being 0 C=273 K)
- P2= ?
- T2= 100 K
Replacing:

Solving:

P2= 0.54 atm
<u><em>Its pressure will be 0.54 atm at 100 K.</em></u>
<u>Q</u><u>U</u><u>E</u><u>S</u><u>T</u><u>I</u><u>O</u><u>N</u><u> </u><u>:</u>
- highest energy level for lithium
<u>A</u><u>N</u><u>S</u><u>W</u><u>E</u><u>R</u><u> </u><u>:</u>
- There are 2 electrons on the first energy level and 1 electron on the second. Explain that the first energy level can only have 2 electrons so the next electron in lithium is on the next (second) level. Explain that neon has 10 protons and 10 electrons.