Answer:
Five molecules of oxygen.
Explanation:
Hello,
In this case, considering the given chemical reaction, we must write a five before the oxygen in order to equal the number of oxygen atoms at both the right and left side (ten) so phosphorous remain the same (4):

It means that five molecules of oxygen (O₂) are needed to form one molecule of tetraphosphorous decaoxide (P₄O₁₀).
Best regards.
It should be 0.25 M. Use the formula C1*V1=C2*V2, for those values, as it is right when it changed colour. Remember to change the if those are not the same (but in your case it is, so no need this time).
C1*V1=C2*V2
C1*27ml=0.55M*12.5ml
C1=(0.55M*12.5ml)/27ml = 0.25M
Hey there!:
Molar mass Ca(NO2)2 = 132.089 g/mol
Mass of solute = 120 g
Number of moles:
n = mass of solute / molar mass
n = 120 / 132.089
n = 0.0009084 moles of Ca(NO2)2
Volume in liters of solution :
240 mL / 1000 => 0.24 L
Therefore:
Molarity = number of moles / volume of solution
Molarity = 0.0009084 / 0.24
Molarity = 0.003785 M
Hope that helps!
Specific heat capacity (c) of a material is related to the Energy Absorbed (Q), mass of the material (m) and the change in temperature (T) by the following equation:

Substituting the values of Q, m and T in the above equation, we get:

So the specific heat capacity of the metal with given conditions will be 0.129 J/g.K