A 1.775g sample mixture of KHCO₃ is decomposed by heating. if the mass loss is 0.275g, the mass percentage of KHCO₃ is 70.4%.
<h3>What is a decomposition reaction?</h3>
A decomposition reaction can be defined as a chemical reaction in which one reactant breaks down into two or more products.
- Step 1: Write the balanced equation for the decomposition of KHCO₃.
2 KHCO₃(s) → K₂CO₃(s) + CO₂(g) + H₂O(l)
The mass loss of 0.275 g is due to the gaseous CO₂ that escapes the sample.
- Step 2: Calculate the mass of KHCO₃ that formed 0.275 g of CO₂.
In the balanced equation, the mass ratio of KHCO₃ to CO₂ is 200.24:44.01.
0.275 g CO₂ × 200.24 g KHCO₃/44.01 g CO₂ = 1.25 g KHCO₃
- Step 3: Calculate the mass percentage of KHCO₃ in the sample.
There are 1.25 g of KHCO₃ in the 1.775 g sample.
%KHCO₃ = 1.25 g/1.775 g × 100% = 70.4%
A 1.775g sample mixture of KHCO₃ is decomposed by heating. if the mass loss is 0.275g, the mass percentage of KHCO₃ is 70.4%.
Learn more about decomposition reactions here: brainly.com/question/14219426
Answer:
A.
Explanation:
melting of ice will increase water in oceans due to which water in oceans will increase and salinity will decrease. hence, melting of ice caps near the north pole affects salinity of the ocean
This problem is providing the heating curve of ethanol showing relevant data such as the initial and final temperature, melting and boiling points, enthalpies of fusion and vaporization and specific heat of solid, liquid and gaseous ethanol, so that the overall heat is required and found to be 1.758 kJ according to:
<h3>Heating curves:</h3>
In chemistry, we widely use heating curves in order to figure out the required heat to take a substance from a temperature to another. This process may involve sensible heat and latent heat, when increasing or decreasing the temperature and changing the phase, respectively.
Thus, since ethanol starts off solid and end up being a vapor, we will find five types of heat, three of them related to the heating-up of ethanol, firstly solid, next liquid and then vapor, and the other two to its fusion and vaporization as shown below:
Hence, we begin by calculating each heat as follows, considering 1 g of ethanol is equivalent to 0.0217 mol:
![Q_1=0.0217mol*111.5\frac{J}{mol*\°C}[(-114.1\°C)-(-200\°C)] *\frac{1kJ}{1000J} =0.208kJ\\ \\ Q_2=0.0217mol*4.9\frac{kJ}{mol} =0.106kJ\\ \\ Q_3=0.0217mol*112.4\frac{J}{mol*\°C}[(78.4\°C)-(-114.1\°C)] *\frac{1kJ}{1000J} =0.470kJ\\ \\ Q_4=0.0217mol*38.6\frac{kJ}{mol} =0.838kJ\\ \\ Q_5=0.0217mol*87.5\frac{J}{mol*\°C}[(150\°C)-(78.4\°C)] *\frac{1kJ}{1000J} =0.136kJ](https://tex.z-dn.net/?f=Q_1%3D0.0217mol%2A111.5%5Cfrac%7BJ%7D%7Bmol%2A%5C%C2%B0C%7D%5B%28-114.1%5C%C2%B0C%29-%28-200%5C%C2%B0C%29%5D%20%2A%5Cfrac%7B1kJ%7D%7B1000J%7D%20%3D0.208kJ%5C%5C%0A%5C%5C%0AQ_2%3D0.0217mol%2A4.9%5Cfrac%7BkJ%7D%7Bmol%7D%20%3D0.106kJ%5C%5C%0A%5C%5C%0AQ_3%3D0.0217mol%2A112.4%5Cfrac%7BJ%7D%7Bmol%2A%5C%C2%B0C%7D%5B%2878.4%5C%C2%B0C%29-%28-114.1%5C%C2%B0C%29%5D%20%2A%5Cfrac%7B1kJ%7D%7B1000J%7D%20%3D0.470kJ%5C%5C%0A%5C%5C%0AQ_4%3D0.0217mol%2A38.6%5Cfrac%7BkJ%7D%7Bmol%7D%20%3D0.838kJ%5C%5C%0A%5C%5C%0AQ_5%3D0.0217mol%2A87.5%5Cfrac%7BJ%7D%7Bmol%2A%5C%C2%B0C%7D%5B%28150%5C%C2%B0C%29-%2878.4%5C%C2%B0C%29%5D%20%2A%5Cfrac%7B1kJ%7D%7B1000J%7D%20%3D0.136kJ)
Finally, we add them up to get the result:
Learn more about heating curves: brainly.com/question/10481356
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Hope this helps; have a great day!
