Answer:
669.48 kJ
Explanation:
According to the question, we are required to determine the heat change involved.
We know that, heat change is given by the formula;
Heat change = Mass × change in temperature × Specific heat
In this case;
Change in temperature = Final temp - initial temp
= 99.7°C - 20°C
= 79.7° C
Mass of water is 2000 g ( 2000 mL × 1 g/mL)
Specific heat of water is 4.2 J/g°C
Therefore;
Heat change = 2000 g × 79.7 °C × 4.2 J/g°C
= 669,480 joules
But, 1 kJ = 1000 J
Therefore, heat change is 669.48 kJ
There are 1.2 moles of KBr found in 3 Liters of 0.4 M solution.
<h3>HOW TO CALCULATE NUMBER OF MOLES?</h3>
The number of moles of a substance can be calculated by multiplying the molarity by the volume.
No. of moles = Molarity × volume
According to this question, 3L of a KBr solution are contained in a 0.4M.
no. of moles = 3L × 0.4M = 1.2moles
Therefore, there are 1.2 moles of KBr found in 3 Liters of 0.4 M solution.
Learn more about no. of moles at: brainly.com/question/14919968
Answer: In octet state.
Explanation: For noble gases they are stable in state since their outer shell contain fully occupied having 8 electrons.
The mass of Calcium required to complete this reaction is 4.008 g.
- Law of conservation of mass states that In a closed system, mass cannot be produced or destroyed, but it can be changed from one form to another.
- The mass of the chemical constituents before a chemical reaction is equal to the mass of the constituents after the reaction.
- In several disciplines, including chemistry, mechanics, and fluid dynamics, the idea of mass conservation is widely applied.
In the given reaction mass of product after completion of reaction is 13.614 g that means total mass of constituents before reaction should also be 13.614.
So,
mass of Ca + mass of O₂ + mass of S = mass of CaSO4
Ca + 6.400 g + 3.206 g = 13.614 g
mass of Ca = 13.614 - 9.606 = 4.008 g
Therefore, by law of conservation of mass 4.008 g of Ca is required for the completion of the reaction.
Learn more about mass conservation here:
brainly.com/question/2030891
#SPJ9
From own experience, I know that OsO4 is colorless, but Cr2O3 is actually a solid green from what I have seen. but I guess it could appear yellow-greenish.
