1) The chemical equation is
Cu + 2AgNO3 ---> Cu (NO3)2 + 2Ag
2) Molar ratios are as follows:
1 mol Cu: 2 moles AgNO3: 1 mol Cu (NO3)2: 2 mol Ag
3) Converting 12.83 * 10^23 atoms of Cu to moles gives:
12.83 * 10^23 atoms / (6.02 * 10^23 atoms / mol) = 2.131 mol Cu
4) Using the ratios:
2.131 mol Cu * 2 mol Ag / 1 mol Cu = 4.262 mol Ag
5) To convert 4.262 mol of silver to grams, use the atomic weight of silver:
mass = moles × atomic mass = 4.262 mol * 107.9 g / mol = 459.9 grams
Answer: 459.9 g
The answer is - 0.138 M. The buffer pH can be determined using the Henderson equation. Here,
acts as a weak acid and
serves as its corresponding conjugate base. The weak acid has two protons, while the base contains one. The equation can therefore be expressed in terms of protons transferred. Phosphoric acid can donate protons in three stages; the equation we’ve referenced pertains to the second stage, as the acid then has only two protons available and the base only one. Given the concentration of the acid as 0.10 M, we need to calculate the concentration of the base necessary to form a buffer with a pH of exactly 7.0. Substituting the values into the equation leads us to the solution. Cross-multiplying, we find that [base] = 1.38(0.10), yielding [base] = 0.138. Therefore, the concentration of the base needed for the buffer is 0.138 M.
According to the Law, the variation in internal energy (U) of the system is equal to the total of the heat added to the system (q) plus the work performed ON the system (W)
<span>ΔU = q + W </span>
<span>In response to the first question, 0.653 kJ of heat energy is extracted from the system (balloon) while 386 J of work is applied to the balloon, leading to </span>
<span>ΔU = -653J + 386J </span>
<span>=-267J </span>
<span>Thus, the internal energy reduces by 267 J </span>
<span>For the second question, 322 J of heat is supplied to the system (gold bar) while no work is undertaken on the gold bar, marking this as an isochoric/isovolumetric process, thus </span>
<span>ΔU = 322J + 0 </span>
<span>=322J </span>
<span>Hence, internal energy rises by 322 J</span>
Q is determined to be 12.38. The Nernst equation is expressed as Ecell = E°cell - (2.303RT/nF) log Q, where Q represents the reaction quotient. The reaction quotient Q is calculated by taking the product of the products' concentrations divided by the product of the reactants' concentrations. For an electrochemical cell, Q is the concentration ratio of the solution at the anode compared to that at the cathode. Consequently, Q = [anode]/[cathode], specifically Q = 0.052/0.0042, arriving at a value of Q = 12.38.
