If you made the sugar and corn syrup solutions you heated, the sugar made the solutions' boiling points higher than that of pure liquid water.
Answer:
686.43363984 is the answer when 7.8 moles is converted.
Answer:
It connects the two half‑reactions.
Explanation:
A salt bridge is a laboratory device used to connect the oxidation and reduction of half-cells of a galvanic cell. It prevents the cell from rapidly running its reaction to equilibrium.
Salt bridge or a porous plate connects the solutions of the half-cells that allow ions to pass from one solution to the other. This process balances the charges of the solutions and allows the reaction to continue.
C)
Explanations
Approach A: Comparison of the bonding atoms
What element(s) does each species comprise?
- carbon monoxide- one metalloid, carbon, bonded to one nonmetal
- oxygen- one nonmetal
- lithium bromide- one metal and one nonmetal
- ammonia- two nonmetals
Lithium bromide is the only substance that features a metal element bonded to a nonmetal element among all four species in the list. It takes significant differences in electronegativity for the bonding atoms in a binary compound to ionize and form an ionic compound. Therefore the species in question shall contain at least one metal element bonded to one nonmetal.
Approach B: Comparison of melting points
Recall the physical state of the species under room temperature and pressure:
- carbon monoxide- gas
- oxygen- gas
- lithium bromide- ?
- ammonia- gas
Ionic bonds hold ions in an ionic compound in place with great degrees of rigidity. In contrast, covalent molecules adhere to each other with intermolecular interactions that are weaker by magnitudes. It's unlikely for ionic crystals to behave as gases under standard conditions. Thus A, B, D cannot be ionic compounds.
1) Chemical reaction
HCl + NaOH ---> NaCl + H2O
25.0 ml
0.150 M 0.250M
2) 50% completion => 0.025 l * 0.150 M * (1/2) = 0.001875 mol HCl consumed and 0.001875 mol HCl in solution
0.001875 mol HCl => 0.001875 mol H(+)
Volume = Volume of HCl solution + Volumen of NaOH solution added
Volume of HCl solution = 0.0250 l
Volume of NaOH = n / M = 0.001875 mol / 0.250M = 0.0075 l
Total volume = 0.0250 l + 0.0075 l = 0.0325 l
[H+] = 0.001875 mol / 0.0325 l = 0.05769 M
pH = - log [H+] = - log (0.05769) = 1.23
Answer: 1.23
3) Equivalence point
0.02500 l * 0.150 M = 0.250M * V
=> V = 0.02500 * 0.150 / 0.250 = 0.015 l
4) 1.00 ml NaOH added beyond the equivalence point
1.00 ml * 1 l / 1000 ml * 0.250 M = 0.00025 mol NaOH in excess
0.00025 mol NaOH = 0.00025 mol OH-
Volume of the solution = 0.02500 l + 0.015 l + 1.00/1000 l = 0.041 l
[OH-] = 0.00025 mol / 0.041 l = 0.00610 M
pOH = - log (0.00610) = 2.21
pH + pOH = 14 => pH = 14 - pOH = 14 - 2.21 = 11.76
Answer: 11.76