Tin(II)nitride :
Formula Sn₃N₂<span>.
</span>
A refractometer is an instrument used to measure the refractive index of gases, liquids, and translucent solids like gemstones. Liquids are tested for things such as blood proteins, salinity, fluid concentrations, and specific gravity of urine.
-130KJ is the standard heat of formation of CuO.
Explanation:
The standard heat of formation or enthalpy change can be calculated by using the formula:
standard heat of formation of reaction = standard enthalpy of formation of product - sum of enthalpy of product formation
Data given:
Cu2O(s) ---> CuO(s) + Cu(s) ∆H° = 11.3 kJ
2 Cu2O(s) + O2(g) ---> 4 CuO(s) ∆H° = -287.9 kJ
CuO + Cu ⇒ Cu2O (-11.3 KJ) ( Formation of Cu2O)
When 1 mole Cu20 undergoes combustion 1/2 moles of oxygen is consumed.
Cu20 + 1/2 02 ⇒ 2CuO (I/2 of 238.7 KJ) or 119.35 KJ
So standard heat of formation of formation of Cu0 as:
Cu + 1/2 02 ⇒ CuO
putting the values in the equation
ΔHf = ΔH1 + ΔH2 (ΔH1 + ΔH2 enthalapy of reactants)
heat of formation = -11.3 + (-119.35)
= - 130.65kJ
-130.65 KJ is the heat of formation of CuO in the given reaction.
The answer is balanced forces
Answer:
The answer to your question is letter A
Explanation:
Data
Mass ratio 1.62 to 1.00
Atomic mass Cr = 52 g
Atomic mass O = 16
Process
1.- Calculate the proportion Chromium to Oxygen to each possible solutions
a) CrO₃ = 
b) CrO₂ = 
c) CrO = 
d) Cr₂O = 
