Correct answer: B
Cooling curve is the plot of temperature versus time as the sample is allowed to cool. In a cooling curve, we start at a temperature greater than the boiling point. At this temperature, the sample is in gaseous state. At the boiling point, there is no change in temperature as the gaseous and liquid states are in equilibrium. As the temperature reduces further, the liquid starts to condense and at the melting point of the sample the liquid undergoes phase transition to solid state. At the melting temperature, a second plateau is observed as the temperature remains unchanged. At temperatures below the melting point, the sample exists as a solid.
So from the curve, the second plateau is observed at around -111
. This point represents the phase transition from liquid to solid state.
Answer:
what is the net ionic equation
H2SO4(aq) + Cal2(aq) → CaSO4(s) + 2Hl(aq)?
A. H++ SO42- + Ca2+ + 21 → CaSO4 + H+ +1-
B. 2H+ + S042- + Ca2+ + 21° → Ca2+ + SO42- + 2H+ + 21
C. S042- + Ca2+ → CaSO4,
D. 2H+ + SO42- + Ca2+ + 2I- → CaSO4 + 2H+ + 2I-
cancel the spectator ion that is the ions which does not take place in the reaction
for this case is 2 H^+ and 2 i^-
Answer:
Ammonia (NH3)
Explanation:
its an ionic compound where N nitrogen is bonded to covalent molecules
Answer:
a. The apparatus required to purify gypsum sample are: Bunsen burner, beaker, Filter Funnel, stirring rod, the filter paper.
b. Gypsum is a sulfate mineral that is made up of calcium sulfate dihydrate. Step-by-step instruction to purify gypsum sample is as follows:
1. Add water to the gypsum sample in a beaker.
2. Use the stirring rod to mix the mixture well.
3. Filter off the excess solid from the mixture using the filter paper and filter funnel.
4. Put the filtered mixture over the bunsen burner and evaporate the excess water from the mixture.
5. Allow the hot liquid to cool down and filter it again through the filter paper to get the pure gypsum.
To insert a thermometer into an adapter, use <u>mineral oil</u> to prepare the thermometer. Then, hold the thermometer <u>close to</u> the adapter and<u> slowly turn</u> the thermometer into the adapter.
The term "temperature" refers to a measurement of how cold or hot an actual physical object is. It is measured with a thermometer, which gives readings in Celsius, Kelvin, and Fahrenheit (°C, K, and °F).
The average kinetic energy of the particles in a given substance is often measured by temperature. A thermometer is a tool used to gauge a substance's or a body's temperature (degree of hotness or coolness). It is a bulb-shaped piece of thin glass that usually contains either coloured alcohol or mercury.
In order to get readings throughout the distillation process, a thermometer adapter is used with a temperature probe. Use mineral oil to prepare or make the thermometer suitable before inserting it into the adapter. After that, slowly insert the thermometer into the adaptor while holding it close to it.
Learn more about thermometer:
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