9)
balanced equation: CuSO₄ + Zn(s) ---> ZnSO₄ + Cu(s)
reaction type: single replacement
10)
balanced equation: H₂O₂ ----> H₂O + O₂ catalyst MnO2 under the arrow.
reaction type: decomposition
Particles that orbit the nucleus are called electrons.
Explanation: Electrons are negatively charged particles arranged in orbits around the nucleus of an atom and determining all of the atom's physical and chemical properties except mass and radioactivity.
<em>Answer:</em>
<em>242 gram</em> of HF will be required for complete rex.
<em>Balance chemical equation:</em>
SiO2 + 4HF → SiF4 + 2H2O
<em>Data given</em>
mass of SiO2 = 182g
molar mass of SiO2=60.08
moles of SiO2 = mass/molar mass = 182/60.08 =3.02 moles
From balance chemcial equation
SiO2 : HF
1 : 4
3.02 = 4 × 3.02 = 12
mass of HF= no. of moles × molar mass
mass of HF = 12.08×20 =<em> 242 g</em>