Which of the following are double-displacement reactions? multiple answers A. 2H2(g) + O2(g) -> 2H2O(g)
B. Zn(s) + 2HCI(aq) -> H2(g) + ZnCI2(s)
C. Ba(OH)2(aq) + 2HCIO4(aq) -> Ba(CIO4)2(aq) + 2H2O(I)
D. HNO3 (aq) + KOH (aq) -> H2O(I) + KNO3 (aq)

Aclarinetist, setting out for a performance, grabs his 3.350 kg clarinet case (including the clarinet) from the top of the piano and carries it through the air with an upward force of 24.65 n. find the case's vertical acceleration. indicate an upward acceleration as positive and a downward one as negative.

An engine undergoes a cycle as shown in the diagram. during a complete cycle the work done by the gas is 28.5×103 j and the energy transferred thermally out is 99.4×103 j. there are 1.5×1024 gas molecules and they have three active degrees of freedom. 6. (6 pts) during which process(es) is energy transferred thermally into the gas? a. 1→2 b. 2→3 c. 4→1 d. 1→2 and 4→1 e. none of the above

Most of the volume of an atom is occupied by the