The answer is; The spectrum of a star shifts towards the blue region when the star moves towards Earth.
This is referred to as the Doppler shift effect. As the star moves closer to the observer, the wavelength of light it produces is ‘compressed’ hence changing its relative frequency (just like the pitch of the siren of an ambulance approaching you).
Feldspar is Soft but sometimes can be hard if a chemical reaction occurs
Answer : The standard enthalpy change for the combustion of CO(g) is, -283 kJ/mol
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The combustion of
will be,

The intermediate balanced chemical reaction will be,
(1)

(2)

Now we are reversing reaction 1 and then adding both the equations, we get :
(1)

(2)

The expression for enthalpy change for the reaction will be,



Therefore, the standard enthalpy change for the combustion of CO(g) is, -283 kJ/mol
Answer:
Rate of the reaction= 9.92× 10^-5 M² min-1
Explanation:
Using the equation of reaction
2N2O5 ⟶ 4NO2+O2
Rate = k[N2O5]²
From the question k= 6.2×10-4
[N2O5]= 0.4
Rate = 6.2×10-4[0.4]²= 9.92×10-5M² min-1