Answer:
<em>C</em> C2H5OH = 7.598 molal
Explanation:
- molality (m) C2H5OH = n C2H5OH / Kg H2O
∴ V C2H5OH = 50.0 mL
∴ V H2O = 112.7 mL
∴ T = 20 °C
∴ δ C2H5OH (20°C) = 0.789 g/mL
∴ δ H2O (20°C) = 1.00 g/mL
∴ Mw C2H5OH = 46.0684 g/mol
⇒ n C2H5OH = (50.0 mL)×(0.789 g/mL)×(mol/46.0684 g) = 0.8563 mol
⇒ mass H2O = (112.7 mL)×(1.00 g/mL)×(Kg / 1000 g) = 0.1127 Kg
⇒ <em>C</em> C2H5OH = 0.8563 mol C2H5OH / 0.1127 Kg H2O
⇒ <em>C</em> C2H5OH = 7.598 molal
Answer:
100 cg/1g
Step-by-step explanation:
1 cg = 0.01 g Multiply by 100
100 cg = 1 g
(a) is <em>wrong</em>. The correct conversion factor is 1000 cm³/1 L.
(b) is <em>wrong</em>. The correct conversion factor is 1000 mL/1 L.
(c) is <em>wrong</em>. The correct conversion factor is 1 m/10 dm.
The closeness of a measurement to its true value is a measure of its accuracy. This term is the degree of which a certain measurement conforms to the correct value or the standard value. It is not the same with the term precision. Precision, on the other hand, is a measure used to characterize the closeness of the data measured.
Answer:
form an aqueous solution
Explanation:
The same substance is present before and after the change. Making the aqueous solution is physical change.