Answer : if you have time for learning and is in 6th grade the anwser is crocodilians
Explanation: i got it right
The Thiele tube which is look like a triangle, used for the determination of melting and boiling point of the solid and liquid sample respectively. The tube consists of high viscous oil. The mouth of the triangle tube consists the thermometer and the sample through a rubber stopper. The tube is always heated in low flame as the heating mechanism of the oil is through convection current process, in which the molecules of the oil heated passes through out the bulk to make a uniform heat of the liquid. The uniform heat of the liquid is necessary to determine the exact melting point of the solid. Also the low heating rate is compulsory so that the rate of convection current be slow. The high heating rate may cause fast convection in the oil and the hot oil can spill out from the tube and may cause an accident.
From the data obtained from the tests, the actual boiling point lies between 34°C and 40°C.
The boiling point of a substance is the temperature at which the pressure of the substance becomes equal to atmospheric pressure. Pure substances have a sharp boiling point while impure substances boil over a temperature range.
In this case, the boiling point of the substance after 10 tests is obtained as 37+/−3°C. This implies that the actual boiling point lies between 34°C and 40°C.
Learn more: brainly.com/question/8646601
20 calories equals to 8.368 joules.
4.184 J is needed to raise 1 gram of water.(Heat capacity of water)
for 2 grams of water 8.368 joules.
So the answer is 16 c.
Answer:
B. - 210 kJ
Explanation:
<em>∵ ΔHrxn = ∑(bond energies)products - ∑(bond energies)reactants.</em>
- The bond formation in the products releases energy (exothermic).
- The bond breaking in the reactants requires energy (endothermic).
The products:
- H₂O contains 2 O-H (- 459 kJ/mol) bonds.
- O₂ contain 1 O=O (- 494 kJ/mol) bond.
The reactants:
- H₂O₂ contain 2 O–H (459 kJ/mol) bonds and 1 O–O (142 kJ/mol) bond.
∵ ΔHrxn = ∑(bond energies)products - ∑(bond energies)reactants.
<em>∴ ΔHrxn = [2 (2 x (O–H bond energy) + (1 x (O=O bond energy)] - 2 [(2 x (O–H bond energy) + (1 x (O–O bond energy)] </em>= [2 (2 x - 459 kJ/mol) + (1 x - 494 kJ/mol)] - 2 [(2 x 459 kJ/mol) + (1 x 142 kJ/mol)] = (- 2330 kJ) + (2120 kJ) = <em>- 210 kJ.</em>
