Im unsure :( maybe try looking up a calorie calculator
Answer is (4) - Pb.
According to the reactivity series of elements
- the elements which are above the hydrogen are more reactive than hydrogen.
- the elements which are below the hydrogen are less reactive than hydrogen.
Among the given choices, only Pb is placed above the hydrogen in the reactivity series and rest are below the hydrogen.
Hence, Pb is more active than hydrogen.
1st one= CaO +H2O=Ca(OH)2
product side-
Ca=1
O=2
H=2
Reactant side-
Ca=1
O=2
H=2
The first one is balanced for you
There is 1 calcium on each side 2 oxygens on each side and 2 hydrogens on each side
M C C O R M I C K T E A M ’ S O P E N Q U A N T U M M AT E R I A L S D ATA B A S E
O F F E R S U N L I M I T E D A C C E S S T O
ANALYSES OF NEARLY 300,000 COMPOUNDS
Answer:
This is heating limestone
Explanation:
Process:
limestone is heated strongly. After a while, the limestone begins to go cloudy. Test tube is heated too much that it is beginning to soften it. After removing limewater, test tube cools down, the pressure in the test tube drops and air pressure pushes the cold the liquid into the hot test tube with terrible result.
Products:
Limestone is also known as calcium carbonate and Limewater
Click on the link provided to show the video
https://youtu.be/RLL5rT_DeKc
or search heating calcium carbonate
you will find a video
