Letter C would be the correct answer
Answer:
a solution color becoming less intense due to dilution- is not an evidence of a chemical reaction
bubbles (gas formation) - evidence of a chemical reaction
explosion or fire - evidence of a chemical reaction
changes in color- evidence of a chemical reaction
precipitation- evidence of a chemical reaction
changes in temperature - evidence of a chemical reaction
a solid liquifying - is not an evidence of a chemical reaction
solution colors mixing - is not an evidence of a chemical reaction
Explanation:
A chemical change is not easily reversible and yields new substances. It is often accompanied by a loss or gain of heat.
In the answer section, i have shown some evidences that lead us to conclude that a chemical reaction has taken place. The occurrence of a chemical change often goes with the formation of new substances as earlier stated and any of these signs may accompany the process.
For instance, when a metal is dropped in dilute acid solution, bubble of hydrogen gas indicates that a chemical reaction has taken place.
Hi,
To solve the question, first of all we will find out the no. of moles of H2SO4 in 19 g of sulfuric acid.
As we know:
No . of moles = Mass/ Molar mass
No. of moles= 19 g/98.08
g
No. of moles= 0.1937
Now we know the no of moles of H2SO4 that will react with 2LiOH. We also know the molar equivalence of H2SO4 , and 2LiOH that will react.
So, the water that will be produced will be 2H2O and 1 Li2SO4 when H2SO4 that will react with 2LiOH.
0.1937 x 2x 18.01
=6.977
=6.98
Therefore, approximately 6.98 grams of water will be produced from 19 g of sulfuric acid.
Hope it helps!
Explanation:
The given data is as follows.
, 
Area of the flat plate is 2 × 4 = 8 
.
Average convection heat transfer coefficient 
= 
= 
.
Hence, formula to calculate heat transfer through convection from air to the water is given as follows.
q = 
= ![60 W/m^{2} ^{o}C} \times 8 m^{2} \times [(80 - 30)]^{o}C](https://tex.z-dn.net/?f=60%20W%2Fm%5E%7B2%7D%20%5E%7Bo%7DC%7D%20%5Ctimes%208%20m%5E%7B2%7D%20%5Ctimes%20%5B%2880%20-%2030%29%5D%5E%7Bo%7DC)
= 24000 W
or, = 24 kW
Hence, the direction of heat flow is from air to the surface.
Thus, we can conclude that transfer of heat is 24 kW.
Hello there,
Rocks that were once swampy sediments or peat beds contain carbon and are black, soft, and fossiliferous<span>.(also known as organic sedimentary rock)
</span>
Hope this helps :)
~Top
