Answer:
2 moles H
2
Explanation:
Your tool of choice here will be the mole ratio that exists between zinc metal,
Zn
, and hydrochloric acid,
:HCl
, in the balanced chemical equation.
Zn
(s]
+
2
HCl
(aq]
→
ZnCl
2(aq]
+
H
2(g]
↑
⏐
You're dealing with a single replacement reaction in which zinc displaces the hydrogen from hydrochloric acid. The products of the reaction are aqueous zinc chloride and hydrogen gas.
Now, as you can see from the balance chemical equation, a
1
:
2
mole ratio exists between the two reactants.
This tells you that in order for the reaction to take place, you need to have twice as many moles of hydrochloric acid as you do of zinc metal.
http://people.springfield.k12.or.us/jim.tyser/chemcom/Resources/unit1ans.html
http://people.springfield.k12.or.us/jim.tyser/chemcom/Resources/unit1ans.html
At the same time, you have a
2
:
1
mole ratio between hydrochloric acid and hydrogen gas.
This means that the reaction will always produce half as many moles of hydrogen gas as you have moles of hydrochloric acid.
Since you know that
4
moles of hydrochloric acid are taking part in the reaction, and assuming that you have enough zinc metal so that it doesn't act as a limiting reagent, you can say that the reaction will produce
4
moles HCl
⋅
1 mole H
2
2
moles HCl
=
2 moles H
2
Explanation:
Answer:
d = 7.9 g/mL
Explanation:
Density:
Density is equal to the mass of substance divided by its volume.
Units:
SI unit of density is Kg/m3.
Other units are given below,
g/cm3, g/mL , kg/L
Formula:
D=m/v
D= density
m=mass
V=volume
Symbol:
The symbol used for density is called rho. It is represented by ρ. However letter D can also be used to represent the density.
Given data:
Mass of brown metal = 14.2 g
Volume = 1.8 mL
Density = ?
Solution:
d = m/v
d = 14.2 g/1.8 mL
d = 7.9 g/mL
Combustion of <span>acetylene :
</span><span>molar ma</span>ss acetylene ( C₂H₂ ) = 26.0 g/mol and CO₂ = 44.0 g/mol
<span>
2 C₂H₂ + 5 O₂ ---> 4 CO₂ + 2 H₂O
</span>
2 moles C₂H₂ --------> 4 moles CO₂
? moles C₂H₂ --------> 1.10 moles CO₂
moles C₂H₂ = 1.10 * 2 / 4
moles C₂H₂ = 0.55 moles of C₂H₂
Mass acetylene:
m = n * mm
m = 0.55 * 26.0
m = 14.3 g
hope this helps!
The answer is B - vegetable oil.
Explanation:
The properties of liquids depend on the attractions the molecules of the liquid have for each other and for other substances.
Liquids can dissolve certain other liquids, depending on the attractions between the molecules of both liquids.
Polar liquids, like water, dissolve other liquids which are polar or somewhat polar.
Polar liquids, like water, do not dissolve non-polar liquids like oil.
Answer:
temperature of the water
Explanation:
Density is defied as mass divided by the volume. To investigate how the density of water change with temperature, Bob have the change the temperature and read the volume and mass of the investigated sample.
Even if there is a different salt content between booted water or tap water and have an influence on the density (compared with pure water), this difference is not so big so the change in density with temperature can be determined. Considering that the experiment do not require extreme accuracy, any type of water may be used (bottled water of tap water).
