Answer:
0.00246kg
Explanation:
1g = $40.63
$100 = $100/40.63 = 2.46g
2.46/1000 g = 0.00246kg
Answer:
B
Explanation:
Since ice is less dense than water, it floats. This forms an ice cover sheet in cold regions such as in the poles. This insulates the water beneath from excessive heat loss hence preventing it from turning into ice too, This protects the marine life beneath. Also, water does not gain heat or loss it rapidly (due to its high heat capacity) hence offering a more or stable temperature range for marine life.
Answer:
It has its elements with mass numbers phrased in many decimal places, it requires one to round off to get the actual value.
The atomic numbers of some elements such as Protonium were just guessed.
Answer:
412.1kJ
Explanation:
For the reaction , from the question -
4Fe (s) + 3O₂ (g) → 2Fe₂O₃ (s)
Δ Hrxn = Δ H°f (products) - Δ H°f (reactants)
In case the compound is in its standard state , enthalphy of formation is zero
Hence ,
for the above reaction ,
ΔHrxn =( 2 * Δ H° (Fe₂O₃ )) - [ ( 4 *Δ H° Fe ) + (3 * Δ H° O₂ )]
The value for Δ H°(Fe₂O₃ ) = - 824.2kJ/mol
Δ H° Fe = 0
Δ H° O₂ = 0
Putting in the above equation ,
ΔH rxn = ( 2 * Δ H° (Fe₂O₃ )) - 0
ΔHrxn = 2× - 824.2 kJ / mol = - 1648.4 kJ/mol
- 1648.4 kJ/mol , this much heat is released by the buring of 4 mol of Fe.
Hence ,
for 1 mol of Fe ,
- 1648.4 kJ/mol / 4 = 412.1kJ
Amount of silver nitrate taken = 269.μmol 
Volume of the solution = 300. mL
Concentration of a solution is generally expressed in terms of molarity. Molarity is defined as the moles of a substance present per liter of the solution.
We want the concentration in millimoles/L.
Converting μmol to millimol solute:
μ
= 0.269 millimol
Volume from mL to L: 
Therefore concentration of the chemist's solution = 
