A student prepared a 0.63 M solution of NaOH with a volume of 92 mL. What was the original concentration if the original volume was 186 mL? Report your answer with 3 decimal places.

Look at the reaction below: ca(hco3)2 --> caco3 + co2 + h2o first, balance the reaction. once balanced, use dimensional analysis or another method to find out how many moles of carbon dioxide will be produced if we start with 16.5 moles of calcium bicarbonate (calcium hydrogen carbonate). = mol of co2 number needs to be reported to three significant figures.

Two nitro no2 groups are chemically bonded to a patch of surface. they can't move to another location on the surface, but they can rotate (see sketch at right). it turns out that the amount of rotational kinetic energy each no2 group can have is required to be a multiple of ε, where =ε×1.010−24 j. in other words, each no2 group could have ε of rotational kinetic energy, or 2ε, or 3ε, and so forth — but it cannot have just any old amount of rotational kinetic energy. suppose the total rotational kinetic energy in this system is initially known to be 32ε. then, some heat is removed from the system, and the total rotational kinetic energy falls to 18ε. calculate the change in entropy. round your answer to 3 significant digits, and be sure it has the correct unit symbol.

Based on its chemical properties, identify the position of each chemical family on the periodic table.