1) 0.1 M NaCl
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Answer:
160 gm
Explanation:
Five times as much water means you can dissolve 5 times as much potassium nitrate 5 x 32 = 160 gm <u> <===== this seems unlikely though as I doubt 32 g of potassium nitrate will dissolve in only 1 cm^3 of water 1 cm^3 of water is only 1 gm of water </u>
The hypothesis is that salt water freezes faster than fresh water.
The dependent variable is time taken for ice to appear.
The independent variable is presence or absence of salt
The constants are the amount of water in each tray, freezing conditions and length of time of exposure to freezing condition.
The control group is the tray to which salt was not added
The experimental group is the tray to which salt was added
The presence of solutes in a solution causes the freezing point depression.
A solution is made up of a solute and a solvent. In the presence of a solute, the freezing point of a pure solvent is decreased. This is because freezing point is a colligative property.
Colligative properties depend on the amount of solute present.
Hence, the pure water freezes faster (ice begin to appear earlier) than the salt water.
The hypothesis put forward in this experiment was found to be invalid by the experiment.
For more about colligative properties, see
brainly.com/question/10323760
Answer:
the original concentration of A = 0.0817092 M
Explanation:
A reaction is considered to be of first order it it strictly obeys the graphical equation method.
where;
k = the specific rate coefficient = 3.4 × 10⁻⁴ s⁻¹
t = time = 5.0 h = 5.0 × 3600 = 18000 seconds
a = initial concentration = ???
a - x = remaining concentration of initial concentration at time t = 0.00018 mol L⁻¹
a = 0.0817092 M
Thus , the original concentration of A = 0.0817092 M
