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:
The answer to your question is 22.4 g of Ca(NO₃)₂
Explanation:
Data
mass of Ca(NO₃)₂ = ?
mass of water = 726 g
concentration = 0.2 m
Process
In Chemistry, there are two main units of concentration Molarity (M) and Molality (m). In this problem concentration is "m" then I will calculate molality.
1) Formula
molality = moles / mass of solvent
2.- Solve for moles
moles = molality x mass of solvent
-Substitution
moles = (0.2) x (0.726)
-Simplification
moles = 0.1452
3.- Convert moles to grams
Molar mass of Ca(NO₃)₂ = 40 + (14 x 2) + (6 x 16)
= 40 + 18 + 96
= 154 g
154 g of Ca(NO₃)₂ ---------------- 1 mol
x ---------------- 0.1452 moles
x = (0.1452 x 154) / 1
x = 22.4 g of Ca(NO₃)₂
Hi!
The reason for reviewing and replicating work of other scientists is influenced by two factors listed in the answer:
1. An experiment may have had errors that the scientist did not recognize. <u>(unintentional) </u>
2. The results of individual scientists may be influenced by bias. <u>(intentional)</u>
<em>Personal motivations may often influence a scientist to manipulate the results to best suit his/her hypothesis, consequently leading to scientific fraud. </em>
While other options listed are elements of the scientific method, they are not the reasons behind the review and replication of a scientist's work by others.
Explanation:
The energy we use in our homes tends to be provided by coal, gas, and oil. These three "fossil fuels" are underground supplies of energy, created millions of years ago, that we drill, mine, or pipe to the surface to satisfy our energy needs today. Most of the energy we use in our vehicles also comes from oil
