To most geologists, the term "acid test" means placing a drop of dilute (5% to 10%) hydrochloric acid on a rock or mineral and watching for bubbles of carbon<span> dioxide gas to be released. The bubbles signal the presence of carbonate minerals such as</span>calcite<span>, </span>dolomite<span>, or one of the minerals listed in Table 1.</span>
Answer:
Pb(NO3)2
Cd(NO3)2
Na2SO4
Explanation:
In the first part, addition of HCl leads to the formation of PbCl2 which is poorly soluble in water. This is the first precipitate that is filtered off.
When the pH is adjusted to 1 and H2S is bubbled in, CdS is formed. This is the second precipitate that is filtered off.
After this precipitate has been filtered off and the pH is adjusted to 8, addition of H2S and (NH4)2HPO4 does not lead to the formation of any other precipitate.
The yellow flame colour indicates the presence of Na^+ which must come from the presence of Na2SO4.
answer: the 4 is the product and the other numbers are reactants
Explanation:
i’m pretty sure that’s the answer . i did this last week :)
If these are you choices:
(1) Both the solid and the liquid are good conductors.
(2) Both the solid and the liquid are poor conductors.
(3) The solid is a good conductor, and the liquid is a poor conductor.
(4) The solid is a poor conductor, and the liquid is a good conductor.
Then the answer is number 4. This is because ionic compound conducts electricity when it is dissolved in water.
Answer:
2667 tires are needed to meet the demand of ten homes for one year.
Explanation:
According to the Second Law of Thermodynamics, only a part of generated energy when tires are burned can be utilized due to irreversibilities associated with finite temperature differences. The energy from a tire that can be transformed into electricity (
), measured in kilowatt-hours, is estimated by definition of efficiency:

Where:
- Efficiency, dimensionless.
- Energy liberated by burning, measured in kilowatt-hours.
Given that
and
, the amount of energy per year generated by a tire is:


Now, the amount of tires needed to meet the demand of then homes for one year is:


2667 tires are needed to meet the demand of ten homes for one year.