Moles of Helium = 2
<h3>Further explanation</h3>
Given
12.04 x 10²³ atoms of helium
Required
moles
Solution
The mole is the number of particles(molecules, atoms, ions) contained in a substance
1 mol = 6.02.10²³ particles
Can be formulated
N=n x No
N = number of particles
n = mol
No = Avogadro's = 6.02.10²³
moles Helium :
n = N : No
n = 12.04 x 10²³ : 6.02 x 10²³
n = 2
The coefficients : 3, 2, 1,3
<h3>Further explanation</h3>
Given
Reaction
Mg + H3PO4 -> Mg3(PO4)2 + H2
Required
The coefficients
Solution
Steps to balance reactions:
1. Give a coefficient(The most complex compound is assigned a coefficient of 1)
aMg + bH₃PO₄ ⇒ Mg₃(PO₄)₂ + cH₂
2. Make an equation
Mg, left = a, right = 3 ⇒a=3
P, left = b, right = 2⇒b=2
H, left = 3b, right = 2c⇒3b=2c⇒3.2=2c⇒2c=6⇒c=3
The equation becomes :
<em>3Mg + 2H₃PO₄ ⇒ Mg₃(PO₄)₂ + 3H₂</em>
-1 because each electron holds a charge of -1 and each proton has a charge of +1 and the neutrons have no charge.
The answer for the following problem is mentioned below.
Explanation:
Given:
mass of iron (m) = 15.75 grams
heat (q) = 1097 J
initial temperature () = 25°C
final temperature () = 177°C
To find:
specific heat (c)
We know;
c = q ÷ mΔT
where;
c represents the specific heat
q represents the heat
m represents the mass
t represents the temperature
c =
c = 0.45 J/kg°C
<u><em>Therefore the specific heat capacity of iron is 0.45 J/kg°C.</em></u>