HRS - Ask. Learn. Share Knowledge. Logo

Questions in chemistry

[Done] An energy value of \(3.313 \times 10^{-19}\) joules is needed to break a chemical bond. What is the wavelength of energy needed to break the bond? (The speed of light, \(c\), is \(3.00 \times 10^{10}\) cm/sec; Planck’s constant, \(h\), is \(6.626 \times 10^{-34}\) J⋅sec). A. \(5.00 \times 10^{18}\) cm B. \(1.00 \times 10^{15}\) cm C. \(2.00 \times 10^{5}\) cm D. \(6.00 \times 10^{-5}\) cm E. \(1.20 \times 10^{-8}\) cm Can someone explain to me how to solve this step by step?

[Done] How many main layers does the planet we call Earth have?

[Done] The maximum energy available for useful work from a spontaneous reaction: A. free energy B. lattice energy C. kinetic energy D. activation energy E. ionization energy

[Done] Which of the following aqueous solutions would have the greatest freezing-point depression? A. 0.10 m (NH₄)₂SO₄ B. 0.10 m MnSO₄ C. 0.10 m NaF D. 0.10 m KCl E. 0.10 m CH₃OH

[Done] Which of the following was NOT a conclusion of Rutherford’s gold foil experiment? A. The atom is mainly empty space B. The nucleus has a negative charge C. The atom has a dense nucleus D. Alpha particles can pass through a thin sheet of gold foil E. All of the above are correct regarding the gold foil experiment

[Done] The ionization energy of an element is: a. a measure of its mass b. the energy required to remove an electron from the element in its gaseous state c. the energy released by the element in forming an ionic bond d. the energy released by the element upon receiving an additional electron e. none of the above

[Done] A change of phase never accompanies: a. a change in volume b. a change in pressure c. a change in temperature d. a change in density e. a change in structure

[Done] Define and compare boiling point, melting point, and freezing point.

[Done] You heat a piece of iron from 200 K to 400 K. What happens to the energy of random motion of the atoms?

[Done] A 30.00 mL solution of 0.100 M benzoic acid, a monoprotic acid, is titrated with 0.100 M NaOH. The [tex]$K_a$[/tex] is [tex]$6.3 \times 10^{-5}$[/tex]. Determine the pH of the solution after the following volumes of NaOH are added: a. 0 mL b. 10.00 mL c. 30.00 mL d. 40.00 mL