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.
Answer:
Explanation:
1. Write the equation for the reaction.
M_r: 24.30
MgCl₂ ⟶ Mg + Cl₂
m/g: 60.0
2. Calculate the moles of Mg
Moles of Mg = 60.0 g Mg × (1 mol Mg/ 24.30 g Mg) = 2.469 mol Mg
3. Calculate the moles of electrons
Moles of electrons = 2.469 mol Mg × (2 mol electrons/1 mol Mg)
= 4.938 mol electrons
4. Calculate the number of coulombs
Q = 4.938 mol electrons × (96 485 C/1 mol electrons) = 476 500 C
5. Calculate the current required
Q = It
I = Q/t
t = 2.00 h × (60 min/1h) × (60 s/1 min) = 7200 s
I = 476 500 C/7600 s= 66.2 C/s = 66.2 A
You need a current of 
.
Answer:
Mass: 981.0 g
Density: 5.61 g/cm^3
Hardness: = 2.5 - 3
Unknown material: Chalcocite
Explanation:
