A student dissolves 5.00 g calcium hydroxide to make 100.0 mL of solution. If 63.5 mL of this solution is required to neutralize 150.0 mL of a hydrofluoric acid solution, what is the concentration of the original HF solution

The identities of substances are the same before and after which type of change

Suppose a pair of chemical compounds a and b can react in two different ways: a + b -> c reaction 1 gives product c. a + b -> d reaction 2 gives product d. the following facts are known about the two reactions: . reaction 1 is endothermic and reaction 2 is exothermic. if a reaction vessel is charged (filled) with a and b , then at first d is produced faster than c. use these facts to sketch a qualitative reaction energy diagram for both reactions. note: because these sketches are only qualitative, the energies don? t have to be exact. they only have to have the right relationship to each other. for example, if one energy is less than another, that fact should be clear in your sketch.

Spaghetti sauce can be high in sodium. what is a good guideline for mg of sodium per half cup serving? a. less than 1 mg b. less than 800 mg c. less than 700 mg d. less than 400 mg