when sodium metal is dropped in water, hydrogen gas in liberated due to extreme heat released as the reaction is exothermic, gas catches fire.
Answer:
1) Endothermic.
2) 
3) 
Explanation:
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1) In this case, for these calorimetry problems, we can realize that since the temperature decreases the reaction is endothermic because it is absorbing heat from the solution, that is why the temperature goes from 22.00 °C to 16.0°C.
2) Now, for the total heat released by the reaction, we first need to assume that all of it is released by the solution since it is possible to assume that the calorimeter is perfectly isolated. In such a way, it is also valid to assume that the specific heat of the solution is 4.184 J/(g°C) as it is mostly water, therefore, the heat released by the reaction is:
3) Finally, since the enthalpy of reaction is calculated by dividing the heat released by the reaction over the moles of the solute, in this case NH4Cl, we proceed as follows:
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Answer : It is a conclusion.
Explanation:
Conclusion: It is a judgement or decision which can be attained by reasoning.
From the observation table given we can conclude that :
- Aluminum ,bronze and steel took 27,45 and 80 seconds to melt small piece of wax respectively which means that more time will be required by them to transfer heat to the food while cooking. Hence, food will take more time to cook in them.
- Copper took less time of 15 seconds to melt the small piece of wax in comparison to other metal pots which means that it is a good conductor of heat in comparison to other. Hence, copper pot would be better for cooking food quickly.
After analyzing the observations and results in an experiment conclusion was made that copper pots are best for cooking foods.
Two radius of an atom is equal to the diameter. Adding up all the diameter of the atoms, it should be equal to 9.5 mm. Therefore, we simply convert the units to the same units then divide 1.35 A to 9.5 mm. We calculate as follows:
no. of atoms = 0.0095 m / 1.35x10^-9 m = 7037037 atoms
Hope this answers the question. Have a nice day.
Answer:
lithium=atomic no.=3
Explanation:
-1 charge on lithium means one electron has added to it .Thus,
Li-1=no. of electrons=3+1=4
