Answer:
86,400 seconds in a day.
Explanation:
There are 24 hrs in a day. So there are 2460 mins in a day. ( 1hr=60 mins) So there are 246060 seconds in a day. (1 min = 60 seconds) Therefore 86,400 seconds in a day.
If the results of the experiment on repeating are not same, it shows the results are not standard, there are some factors, which are not constant
Answer:
The overview of the subject is outlined underneath in the summary tab.
Explanation:
- The molar ratio seems to be essentially a balanced chemical equilibrium coefficient that implies or serves as a conversion factor for the product-related reactants.
- This ratio just says the reactant proportion which reacts, but not the exact quantity of the reacting product. Consequently, the molar ratio should only be used to provide theoretical instead of just a definite mass ratio.
The volume of hydrogen gas that evolved is calculated as follows
by use of ideal gas equation
that is PV = nRT
P=745 mm hg
V= ?
R(gas constant)= 62.36 L.mm hg/mol.k
T= 20 + 273 = 293 k
n=number of moles which is calculated as follows
find the moles of Na used
= 0.52/23=0.023 moles
write the reacting equation
2Na +2H2O =2NaOH +H2
by use of reacting ratio between Na : H2 which is 2:1 therefore the mole of H2 = 0.023/2 =0.0115 moles
by making the volume the subject of the formula
v=nRT/P
V= (0.0115 x 62.36 x 293) / 745 = 0.283 L
Answer:
C) Chemical changes involve formation of a new substance while physical change only impacts appearance or form.
Explanation:
The obvious difference between a chemical change and physical change is that in a chemical change new substances are produced while in a physical change, the form of the compounds are altered.
- Most phase changes are products of physical changes. Such changes are easily reversible.
- In a chemical change, a new kind of matter is formed. It is accompanied by energy changes.
- The process is not easily reversible.
