Answer is: thermal conductuction.
Thermal conductuction is the transfer of heat<span> through physical contact. </span>Thermal conduction<span> is the transfer of heat</span> by microscopic collisions of particles. <span>Heat spontaneously flows from a hotter to a colder body.
</span>The process of heat conduction depends on four basic factors: the temperature gradient<span>, the cross section of the </span>materials<span> involved, their path length and the properties of those materials.</span>
1) Write the balanced chemical equation
2HCl + Na2 CO3 ----------> 2NaCl + H2CO3
2) Write the molar ratios:
2 mol HCl : 1 mol Na2CO3 : 2 mol NaCl : 1 mol H2CO3
3) Convert 0.15g of sodium carbonate to number of moles
3a) Calculate the molar mass of Na2CO3
Na: 2 * 23 g/mol = 46 g/mol
C: 12 g/mol =
O: 3 * 16 g/mol = 48 g/mol
molar mass = 46g/mol + 12g/mol + 48g/mol = 106 g/mol
3b.- Calculate the number of moles of Na2CO3
# moles = grams / molar mass = 0.15 g / 106 g/mol = 0.0014 mol Na2CO3
4) Calculate the number of moles of HCl from the molar proportion:
[0.0014 mol Na2CO3] * [2 mol HCl / 1 mol Na2CO3] = 0.0028 mol HCl
5) Calculate the volume of HCl from the definition of Molarity
Molarity, M = # moles / volume in liters
=> Volume in liters = # moles / M = 0.0028 mol / 0.1 M = 0.028 liters
0.028 liters * 1000 ml / liter = 28 ml.
Answer: 28 mililiters of 0.1 M HCl.
Answer:
(C) The recrystallization solvent should be nonvolatile.
Explanation:
Recrystallization is the separation technique which is used to purify the solid compounds in their crystal or amorphous form.
Some properties follow the recrystallization process as:
The solids are more soluble in hot solvent as compared to the solubility in the cold solvent.
The solvent must have lower boiling point and can be volatile easily.
The solvent should not react with the compound.
The impurities must be soluble in the cool solvent, so that only the pure product crystallizes.
Hence, Answer - C which is not an ideal characteristic.
The balanced equation for the reaction between NaOH and aspirin is as follows;
NaOH + C₉H₈O₄ --> C₉H₇O₄Na + H₂O
stoichiometry of NaOH to C₉H₈O₄ is 1:1
The number of NaOH moles reacted - 0.1002 M / 1000 mL/L x 10.00 mL
Number of NaOH moles - 0.001002 mol
Therefore number of moles of aspirin - 0.001002 mol
Mass of aspirin reacted - 0.001002 mol x 180.2 g/mol = 0.18 g
However the mass of the aspirin sample is 0.132 g but 0.18 g of aspirin has reacted, therefore this question is not correct.
The formula for molality---> m = moles solute/ Kg of solvent
the solute here is NH₃ because it's the one with less amount. which makes water the solvent.
1) let's convert the grams of NH₃ to moles using the molar mass
molar mass of NH₃= 14.0 + (3 x 1.01)= 17.03 g/ mol
15.0 g (1 mol/ 17.03 g)= 0.881 mol NH₃
2) let's convert the grams of water into kilograms (just divide by 1000)
250.0 g= 0.2500 kg
3) let's plug in the values into the molality formula
molality= mol/ Kg---> 0.881 mol/ 0.2500 kg= 3.52 m
