The balloon's volume is 128 ml when the gas temperature rises to 320.0 K. Explanation: Given the following: T1 (initial temperature) = 300K, V1 (initial volume) = 120ml, T2 (final temperature) = 320 K, V2 (final volume) =?. Pressure is kept constant during this process. From the equation: Given that the pressure stays constant, we have: V2 = Putting the values into this formula yields: V2 = 128 ml, which indicates the volume of the gas when the temperature increases from 300 K to 320 K.
The stronger the attraction between elements, the shorter the bond length becomes; conversely, a weaker attraction results in a longer bond length. This attraction arises from differences in their electronegativities, which is the capacity of an element to draw electrons toward itself. According to periodic trends, electronegativity rises as you move left to right and bottom to top on the periodic table. Therefore, the order from the most electronegative to the least is: Cl > Br > I. As a result, the sequence by bond length from shortest to longest is: C-Cl > C-Br > C-I.
<span>4.3065 g
To begin with, consult the atomic masses for each involved element.
Atomic weight of Calcium = 40.078
Atomic weight of Carbon = 12.0107
Atomic weight of Hydrogen = 1.00794
Atomic weight of Oxygen = 15.999
Atomic weight of Sulfur = 32.065
Next, compute the molar masses of both reactants and the product.
Molar mass H2SO4 = 2 * 1.00794 + 32.065 + 4 * 15.999
= 98.07688 g/mol
Molar mass CaCO3 = 40.078 + 12.0107 + 3 * 15.999
= 100.0857 g/mol
Molar mass CaSO4 = 40.078 + 32.065 + 4 * 15.999
= 136.139 g/mol
The balanced equation for the reaction between H2SO4 and CaCO3 is:
CaCO3 + H2SO4 ==> CaSO4 + H2O + CO2
Thus, 1 mole each of CaCO3 and H2SO4 is necessary to generate 1 mole of CaSO4. Let's check the amount of moles we have for CaCO3 and H2SO4.
CaCO3: 3.1660 g / 100.0857 g/mol = 0.031632891 mol
H2SO4: 3.2900 g / 98.07688 g/mol = 0.033545113 mol
H2SO4 is in slight excess, therefore CaCO3 is the limiting reactant, suggesting we can expect 0.031632891 moles of product. To find the mass, multiply the number of moles by the molar mass calculated previously.
0.031632891 mol * 136.139 g/mol = 4.306470148 g
Given that we have 5 significant figures from our data, we round the final result to 5 figures, yielding 4.3065 g</span>
a) ΔH°rxn = -9.2kJ/mol
b) ΔH°rxn = -9.2kJ/mol
Explanation:
By applying Hess's law, the reaction enthalpy ΔH can be calculated from the enthalpies of formation of the reactants and products involved, thus:
ΔH°rxn = ∑(BE(reactants)) − ∑(BE(products)).
Alternatively, it can be expressed as:
ΔH°rxn = ∑(nΔH°f (products)) − ∑(mΔH°f (reactants)).
For the given reaction:
H₂(g) + I₂(g) → 2HI(g)
a) Using the first equation, we find:
ΔH°rxn = ΔH (H-H) + ΔH (I-I) - 2ΔHBE (H-I)
= 436.4kJ + 151kJ - 2×298.3kJ.
After the calculation, ΔH°rxn is determined to be -9.2kJ/mol.
b) Based on the second equation:
ΔH°rxn = 2ΔH°f (HI) − ΔH°f (H₂) - ΔH°f (I₂).
Substituting the values yields ΔH°rxn = 2×25.9kJ - 0kJ - 61.0kJ.
This also results in ΔH°rxn = -9.2kJ/mol.
a) The completely balanced chemical reaction is:
Zn(s) + H2SO4(aq)
--------> ZnSO4(aq) + H2 (g)
<span>b) Initially, we determine the quantity of zinc that has reacted based on the produced H2.</span>
According to stoichiometry, 1 mole of Zn is required for each mole of H2 created, thus:
moles(Zn) = moles(H2)
where moles are calculated as the ratio of mass to molar mass (MM)
mass(Zn) / MM(Zn) = mass(H2) / MM(H2)
mass(Zn) = [mass(H2) / MM(H2)] * MM(Zn)
mass(Zn) = [(0.0764 g)/(2 g/mol)] * 65.38 g/mol
mass(Zn) = 2.49 g
Consequently, we find 2.49 g of pure zinc in the sample, leading to a purity of zinc of:
purity = (2.49 / 3.86) * 100 % = 64.50 %
<span>c) In part (b), it is assumed that the impurities in the sample do not react with sulfuric acid to emit hydrogen.
Thus, the hydrogen solely arises from the reaction of Zn with sulfuric acid.</span>
