This is a incomplete question.The complete question is:
A chemist adds 180.0 ml of a 1.77 mol/L of sodium thiosulfate solution to a reaction flask. Calculate the mass in grams of sodium thiosulfate the chemist has added to the flask. Be sure your answer has the correct number of significant digits.
Answer: 50.4 g
Explanation:
To calculate the number of moles for given molarity, we use the equation:
.....(1)
Molarity of sodium thiosulfate solution = 1.77 M
Volume of sodium thiosulfate solution = 180.0 mL = 0.1800 L
Putting values in equation 1, we get:

Mass of sodium thiosulfate =
Thus 50.4 g of sodium thiosulfate the chemist has added to the flask.
At the boiling point, external pressure is equal to the vapor pressure of water. Therefore, the vapor pressure of water at an ecternal pressure of 404 kPa is equal to 404 kPa as well. Hope this answers the question. Have a nice day. Feel free to ask more questions.
Answer:
"Like dissolves like" is an expression used by chemists to remember how some solvents work. It refers to "polar" and "nonpolar" solvents and solutes. Like dissolves like, that means polar dissolves polar, so water dissolves salt.
Explanation: