What we want to measure is the taste of coffee.
The following were kept constant during the experimental investigation:
The type of coffee,
The type of percolator,
The same amount and type of water,
The same perking time,
The same electrical sources.
Because these items were kept constant, they are not expected to influence the outcome of the experimental investigation.
Define:
y = the metric used to measure the taste of coffee
x = amount of coffee grounds used for the taste experiment.
Therefore the relationship that arises from the experiment is
y = y(x).
Because x is controllable and is varied during the experiment, it is the independent variable.
Because the measured value of y depends on x, therefore y is the dependent variable.
Answer:
The taste of coffee is the dependent variable.
The amount of coffee grounds used is the independent variable.
It is softer than topaz and and it is softer than diamond (diamond has a Mohs hardness of 10, which is the highest value of the scale)
Explanation:
Since HF is a weak acid, the use of an ICE table is required to find the pH. The question gives us the concentration of the HF.
HF+H2O⇌H3O++F−HF+H2O⇌H3O++F−
Initial0.3 M-0 M0 MChange- X-+ X+XEquilibrium0.3 - X-X MX M
Writing the information from the ICE Table in Equation form yields
6.6×10−4=x20.3−x6.6×10−4=x20.3−x
Manipulating the equation to get everything on one side yields
0=x2+6.6×10−4x−1.98×10−40=x2+6.6×10−4x−1.98×10−4
Now this information is plugged into the quadratic formula to give
x=−6.6×10−4±(6.6×10−4)2−4(1)(−1.98×10−4)−−−−−−−−−−−−−−−−−−−−−−−−−−−−√2x=−6.6×10−4±(6.6×10−4)2−4(1)(−1.98×10−4)2
The quadratic formula yields that x=0.013745 and x=-0.014405
However we can rule out x=-0.014405 because there cannot be negative concentrations. Therefore to get the pH we plug the concentration of H3O+ into the equation pH=-log(0.013745) and get pH=1.86
Answer:
The scientific laws have been well proven before they are published so it is difficult to prove mistakes
Explanation:
