Answer: B: Symbols of Elements
Explanation:
2200 mg of antibiotic
Explanation:
Given that 40 mg of antibiotic/kg of the bodyweight is given.
If patient is 55 kg then the dose of antibiotic will be
if 40/1000000 is done then we can get antibiotic in kg/kg of the weight
= 0.00004 kg of antibiotic per kg
0.00004*55 ( to know how much 55 kg person will require)
= 0.0022 kg
This 0.0022 value will be converted to mg
0.0022*10^6
= 2200 mg of antibiotic will be given to a 55kg patient.
Answer:
C- A proton has about the same mass as a neutron .
Explanation:
In an atom such as a carbon atom, the masses of the proton and neutrons are the same.
The mass of the electrons is very negligible.
- Protons are the positively charged particles in an atom
- Neutrons do not carry any charges
- Both protons and neutrons have similar masses.
- They contribute the bulk of the mass of the atom.
- The electrons carry negative charges and they have negligible masses.
The mass of protons and neutrons are similar.
Percentage Yield = (Actual Yield ÷ Theoretical Yield) × 100
The Actual Yield is given in the question as 21.2 g of NaCl. However, in order to find the theoretical yield, you have to write a balanced equation and use the mole ratio to calculate the mass of NaCl that would be produced.
Balanced Equation: CuCl + NaNO₃ → NaCl + CuNO₃
Moles of CuCl = Mass of CuCl ÷ Molar Mass of CuCl
= 31.0 g ÷ (63.5 + 35.5)g/mol
= 0.31 mol
the mole ratio of CuCl to NaCl is 1 : 1,
∴ if moles of CuCl = 0.31 mol,
then moles of NaCl = 0.31 mol
Now, Mass of NaCl = Moles of NaCl × Molar Mass of NaCl
= 0.31 mol × (23 + 35.5) g/mol
= 18.32 g
⇒ the THEORETICAL Yield of NaCl, in this case, is 18.32 g.
Now, since Percentage Yield = (Actual Yield ÷ Theoretical Yield) × 100
⇒ Percentage Yield of NaCl = (21.2g ÷ 18.32g) × 100
= 115.7 %
NOTE: Typically, the percentage yield of a reaction is less than 100%, however in a case where the mass of the substance is weighed with impurities, then that mass may be in excess of 100% as seen here.
