Answer:
c when electrons drop down from a high energy level they emit a photon.
Explanation:
Answer:
mass HF = 150.05 g
Explanation:
- SiO2(s) + 4HF(g) → SiF4(g) + 2H2O(l)
⇒ Q = (ΔH°rxn * mHF) / (mol HF * MwHF )
∴ MwHF = 20.0063 g/mol
∴ mol HF = 4 mol
∴ ΔH°rxn = - 184 KJ
∴ Q = 345 KJ
mass HF ( mHF ):
⇒ mHF = ( Q * mol HF * MwHF ) / ΔH°rxn
⇒ mHF = ( 345 KJ * 4mol HF * 20.0063 g/mol ) / 184 KJ
⇒ mHF = 150.05 g HF
Answer:0.45L
Explanation:
molarity=0.15M
Mass=5g
No of moles=mass ➗ molecular mass
Molecular mass of KCL=39.0983x1+35.453x1
Molecular mass of KCL=74.5513
No of moles=5 ➗ 74.5513
No of moles=0.067
Volume in liters=No of moles ➗ molarity
Volume in liters=0.067 ➗ 0.15
Volume in liters=0.45L
