The answer is D: studying how the mayfly population affects the number of trout in a stream <span> As the science of ecology studies interactions between individual organisms and their environments.</span>
The equation for calculating a mass is as follows:
m=n×M
Molar mass (M) we can determine from Ar that can read in a periodical table, and a number of moles we can calculate from the available date for N:
n(H2SO4)=N/NA
n(H2SO4)= 1.7×10²³ / 6 × 10²³
n(H2SO4)= 0.3 mole
Now we can calculate a mass of H2SO4:
m(H2SO4) = n×M = 0.3 × 98 = 27.8 g
Answer:
Hint As we know that the concept of mole is mainly to calculate the entities at the microscopic level that is ions, particles, molecules, electrons or atoms etc. It is found that mole is having the symbol mol.
Complete Step by step solution:
- As we are being provided with the information that there is 15 grams of lithium. As we know that the molar mass of lithium is 6.94 g/mol.
- As we know that mole is the amount of substance that has entities as there are atoms exactly in 12 g of carbon isotope. We should note that the number of entities in one mole is important because it is called the Avogadro constant. The numeric value of this constant is 6.022×1023.
- Firstly we will write the given mass as:
156.022×1023
- Now, we can find the number of moles by the formula of moles that is given mass of the substance divided by the molar mass of the substance.
moles=given massmolar mass⟹156.022×10236.94⟹15×6.946.022×1023⟹17.28×10−23moles
- Hence, we can conclude that there are 17.28×1023 moles in 15 grams of lithium.
Note:
- If we want to calculate the number of moles of an individual entity, like say A, that is dissolved in a solution of an entity say B (A+B), then we can do so by using the concept of mole fraction. The formula of mole fraction is given as moles of a substance divided by the total number of moles.
- We should not forget to write the unit after solving the solution. Explanation:
Gold is classified as a Solid
Answer:
92.9 °C
Explanation:
Step 1: Given data
- Initial volume (V₁): 450. mL
- Initial temperature (T₁): 55.0 °C
- Final volume (V₂): 502 mL
Step 2: Convert 55.0 °C to Kelvin
We will use the following expression.
K = °C + 273.15 = 55.0 + 273.15 = 328.2 K
Step 3: Calculate the final temperature of the gas
If we assume constant pressure and ideal behavior, we can calculate the final temperature of the gas using Charles' law.
T₁/V₁ = T₂/V₂
T₂ = T₁ × V₂/V₁
T₂ = 328.2 K × 502 mL/450. mL = 366 K = 92.9 °C
