<span>The solubilties of most ionic solids increase as the temperature increases.
Dissolving of a solid in water is, in most cases, an endothermic
reaction. In dissolving, as in melting, a solid becomes a liquid. It
takes more energy to be a liquid than to be a solid at the same
temperature. When the solution becomes saturated at any temperature, a
dynamic equilibrium is established between the dissolved and undissolved
solid. When heat is added that results in a higher temperature, the
extra heat favors the endothermic reaction, and more solid dissolves
rather than crystallizes until new equilibrium system is established
again. Hence, at a higher temperature, more solid is dissolved in
water. This increases the solid's solubility.
Hope this helps mate =)
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Once you have constructed an effective hypothesis, the next step in the scientific inquiry process is to
test the hypothesis through experimentation. This is a great opportunity for students to start a science
notebook, if they have not yet started recording their progress.
Steps to Identifying and Conducting an Appropriate Experiment to Test a Hypothesis
1) Present Hypotheses
Make a list of all potential hypotheses to be tested.
2) Make Predictions
For each hypothesis, ask what would be true if the hypothesis were true.
3) Write the Experimental Procedure
The experimental procedure is a step-by-step recipe for the science experiment. A good
procedure contains enough detail that someone else could easily duplicate the
experiment. Once you have formed a hypothesis, you will need to develop your
experimental procedure to test whether your hypothesis is true or false.
4) Identify the Independent and Dependent Variables
The first step of designing the experimental procedure involves planning how to change
the independent variable and how to measure the impact that this change has on the
dependent variable. To guarantee a fair test when conducting the experiment, make sure
that the only thing changing is the independent variable. All controlled variables must
remain constant.
5) Design the Experiments
How can you identify an appropriate experiment that will effectively test your
hypothesis? Begin by asking yourselves, “What can I do that will give me one result if my
hypothesis is true, and a different result if my hypothesis is false?” Design at least one
possible experiment for each hypothesis. Be sure that each experiment tests only one
hypothesis.
High iron and magnesium rocks have a high percentage of dark-colored (mafic) minerals.
So the high iron and magnesium would be darker than the low iron and magnesium.
Answer:
The reaction is exothermic (option 4)
Explanation:
P4 + 5O2 → P4O10 + 712 kcal
In chemical reactions heat can be absorbed or released:
⇒in the first case, when heat is absorbed, this is called an endothermic reaction. The products have more energy than the reactants. The reaction requires or absorbs energy from it's surroundings. That means that in this reaction energy , in the form of heat, will be absorbed by the reactants.
⇒ when heat is released, this is called an exothermic reaction. The reactants have more energy than the products. The reaction gives or releases energy to it's surroundings. That means that in this reaction energy , in the form of heat, will be released by the reactants.
in the case of P4 + 5O2 → P4O10 + 712 kcal
We notice that on the right side, which is the product side, there is a positive amount of energy. This means that the energy is released by the the reactants, in this reaction. <u>The reaction is exothermic.</u>
.
Answer:
Option-D: 2.3 × 10⁻³ mol/dm³
Explanation:
Calculate moles of ascorbic acid,
Moles = Mass / M.Mass
Moles = 0.080 g / 176 g/mol
Moles = 0.00045 mole
Also,
Molarity = Moles / Vol. in dm³
Molarity = 0.00045 mol / 0.20 dm³
Molarity = 0.00227 mol.dm⁻¹ or 2.3 × 10⁻³ mol/dm³