The answer that i got was three
i redid it and got some answer like 4.62 x1014<span> Hz</span>
For example, certain medications may influence the results of the test.
Drug test can show the presence of illicit or prescription drugs on hair samples, although the person has not used these drugs.
Some of false positive drug use is because of this medications: antihistamines, decongestants, antibiotics, antidepressants, analgesics and antipsychotics.
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
<span>chemicals reacting are written on the left, what is formed is written on the right after the = sign
eg Copper + oxygen = copper oxide.
Hope this helps , mark as brainliest and say thanks THANKS..</span>
