The question is incomplete, the complete question is;
The table above summarizes data given to a student to evaluate the type of change that took place when substance X was mixed with water. The student claimed that the data did not provide enough evidence to determine whether a chemical or physical change took place and that additional tests were needed. Which of the following identifies the best way to gather evidence to support the type of change that occurred when water and Xwere mixed?
A. Measuring the melting point of the mixture of water and X
B. Adding another substance to the mixture of water and X to see whether a solid forms
C Measuring and comparing the masses of the water, X, and the mixture of water and X
D Measuring the electrical conductivities of X and the mixture of water and X
Answer:
D Measuring the electrical conductivities of X and the mixture of water and X
Explanation:
Unfortunately, I am unable to reproduce the table here. However, from the table, the temperature of the of the mixture of the solid X and water was 101.6°C. This is above the boiling point of water and way below the temperature of the solid X.
This goes a long way to suggest that there was some kind of interaction between the water and X which accounted for the observed temperature of the system of X in water.
The only way we can be able to confirm if X actually dissolved in water is to measure the conductivity of the water. dissolved solids increase the conductivity of water.
It is advisable to wear long sleeve when when a student is working in a chemistry lab so that to protect arms from lab chemicals. when someone enter the chemistry lab to wort or to study should be well prepared with appropriate gears and security measure to avoid injury.
Answer:
0.008945 atm
Explanation:
In the reaction:
2H2S(g) ⇌ 2 H2(g) + S2(g)
Kp is defined as:
<em>Where P is the pressure of each compound in equilibrium.</em>
If initial pressure of H2S is 3.00atm, concentrations in equilibrium are:
H2S = 3.00 atm - 2X
H2 = 2X
S2: = X
Replacing:
0 = 4X³ - 1.28x10⁻⁶X² + 1.92x10⁻⁶X - 2.88x10⁻⁶
Solving for X:
X = 0.008945 atm
As in equilibrium, pressure of S2 is X, <em>pressure is 0.008945 atm</em>
Let's evaluate each choice. For the first choice, this is correct. Hydrosphere consist of all the water's in the Earth's surface. It interacts with the atmosphere through reaeration, so that water cycle continues on. The second option is correct, this is known as the greenhouse effect. The third option is incorrect, because the opposite is true, which makes the fourth option correct. The fifth option is incorrect because the atmosphere has nothing to do with the Earth's crust. <em>So, the answers are: A, B, and D.</em>
