Answer:
The particles in a solid are tightly packed and locked in place. Although we cannot see it or feel it, the particles are moving or vibrating in place.
The mass of NaCl formed is 8.307 grams
<u><em> calculation</em></u>
step 1: write the equation for reaction
Na₂CO₃ + 2HCl → 2 NaCl +CO₂ +H₂O
Step 2: find the moles of Na₂CO₃
moles = mass/molar mass
The molar mass of Na₂CO₃ is = (23 x2) + 12 + ( 16 x3) = 106 g/mol
moles = 7.5 g/106 g/mol =0.071 moles
Step 3: use the mole ratio to determine the mole of NaCl
Na₂CO₃:NaCl is 1:2 therefore the moles of NaCl =0.07 x2 =0.142 moles
Step 4: calculate mass of NaCl
mass= moles x molar mass
the molar mass of NaCl= 23 +35.5 =58.5 g/mol
mass = 0.142 moles x 58.5 g/mol =8.307 grams
<u>Answer:</u> The molecular weight of protein is 
<u>Explanation:</u>
To calculate the concentration of solute, we use the equation for osmotic pressure, which is:
or,
where,
= Osmotic pressure of the solution = 0.0861 atm
i = Van't hoff factor = 1 (for non-electrolytes)
= mass of protein = 400 mg = 0.4 g (Conversion factor: 1 g = 1000 mg)
= molar mass of protein = ?
= Volume of solution = 5.00 mL
R = Gas constant = 
T = temperature of the solution = ![25^oC=[25+273]K=298K](https://tex.z-dn.net/?f=25%5EoC%3D%5B25%2B273%5DK%3D298K)
Putting values in above equation, we get:
Hence, the molecular weight of protein is
