Answer: The precipitate formed is 
Explanation:
A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid or precipitated form are represented by (s) after their chemical formulas.
A double displacement reaction in which one of the product is formed as a solid is called as precipitation reaction.
The balanced chemical equation is:
Answer: A) grinding coffee beans
Explanation:
A physical change is defined as a change in which there is alteration in shape, size etc. No new substance gets formed in these reactions.
A chemical change is defined as a change in which a change in chemical composition takes place. A new substance is formed in these reactions.
1. Grinding coffee : Only change in size takes place, thus a physical change
2. Baking a cake: the chemical reaction occurs by combination of flour with oxygen , thus a chemical change.
3.:converting water to hydrogen and oxygen: The decomposition iof water takes place, thus is a chemical change
4.Burning of coal: the chemical reaction occurs by combination of carbon with oxygen , thus a chemical change.
From the calculation, the standard free energy of the system is -359kJ.
<h3>What is the standard free-energy?</h3>
The standard free-energy is the energy present in the system. We have to first obtain the cell potential using the formula;
Ereduction - E oxidation = 0.96 V - 0.34 V = 0.62 V
Using the formula;
ΔG = -nFEcell
ΔG =-(6 * 96500 * 0.62)
ΔG =-359kJ
Learn more about free energy:brainly.com/question/15319033
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Answer:
Work done, W = 100 J
Explanation:
We have, Billy the friendly Robot uses 50 N of force to lift a box 2 meters in the air.
It is required to find the work done by Billy.
Work done by an object is given in terms of force and displacement. The formula used to find the work done is given by :
So, the work performed by Billy is 100 J.
