WILL GIVE BRAINIEST Charlotte completed an experiment in which she investigated and discovered that an electrically charged object can attract an uncharged object without any contact. She used a PVC pipe and small pieces of paper for her experiment. Each time, she rubbed the PVC pipe with a cloth to give it a charge and then held it over the paper. What would be Charlotte's control group in this experiment? Using the cloth and rubbing it against the PVC pipe

Taking the pieces of paper and rubbing them against the cloth

Not rubbing the cloth against the PVC pipe or the paper

Rubbing the cloth against both the paper and the PVC pipe

The question is incomplete, here is a complete question.

of is 289 J/g.  What mass of this substance must evaporate in order to freeze 190 g of water initially at 17 degrees C? (heat of fusion of water is 334 J/g; specific heat of water is 4.18 J/g.K).  

Answer : The mass of this substance evaporate to freeze must be, 258.2 grams.

Solution :

First we have to calculate the total heat absorbed.

where,

m = mass of water = 190 g

= specific heat of liquid water =

= enthalpy change for fusion of water =

= final temperature =

= initial temperature =

Now put all the given values in the above expression, we get:

Now we have to calculate the mass of substance.

As, 298 J of heat are absorbed by 1 g of

So, 76961.4 J of heat are absorbed by of

Therefore, the mass of this substance evaporate to freeze must be, 258.2 grams.