Answer:
157.79 g
Explanation:
The definition of molality is:
- molality = moles of solute / kilogram of solvent
This means that in a 2.7 molal solution, there are 2.7 moles of NaCl per kilogram of water.
So now w<u>e convert those 2.7 moles of NaCl to grams</u>, using its <em>molar mass</em>:
- 2.7 mol * 58.44 g/mol = 157.79 g
For the reactants,
- The oxidation number of hydrogen = +1
- The oxidation number of oxygen = -2
- The oxidation number of arsenic = +5
- The oxidation number of carbon = +3
For the products,
- The oxidation number of hydrogen = +1
- The oxidation number of oxygen = -2
- The oxidation number of arsenic = +3
- The oxidation number of carbon = +4
Here, arsenic (+5 to +3) and carbon (+3 to +4) are the only oxidation numbers changing.
Note that an increase in oxidation number means electrons are lost. Thus oxidation is occurring, and a decrease in oxidation number means electrons are being gained, and thus reduction is occurring.
Also, the compound that contains the element being oxidized is the reducing agent, and the compound that contains the element being reduced is the oxidizing agent.
So, the answers are:
name of the element oxidized: Carbon
name of the element reduced: Arsenic
formula of the oxidizing agent: 
formula of the reducing agent: 
Answer:
he scientific method has five basic steps, plus one feedback step:
Make an observation.
Ask a question.
Form a hypothesis, or testable explanation.
Make a prediction based on the hypothesis.
Test the prediction.
Iterate: use the results to make new hypotheses or predictions.
Explanation:
I think A.