Answer:
Explanation: The lowest pressure in a laboratory is 4.0×10^-11Pa
Using Ideal gas equation
PV = nRT
P= 4.0×10^-11Pa
V= 0.020m^3
T= 20+273= 293k
n=number of moles = m/A
Where m is the number of molecules and A is the Avogradro's number=6.02×10²³/mol
R=8.314J/(mol × K)
PV= m/A(RT)
4.0×10^-11 ×0.020 = m/6.02×10²³(8.314×293)
m = 4.0×10^-11×0.020×6.02×10^23 / (8.314×293)
m = 1.98×10^8 molecules
Therefore,the number of molecules is 1.98×10^8
In the crystallization process the solid compound is dissolved in the solvent at elevated temperature and the crystallize product obtained by slow cooling of the solution. Here the solubility of acetanilide at 100°C is 1g per 20mL of water. Thus to dissolve 500mg of acetanilide at high temperature that is 100°C we need 10mL of water.
Now at 25°C after the re-crystallization there will be some amount of dissolve acetanilide. Which can be calculated as- 185mL of water is needed to dissolve 1g or 1000mg of acetanilide at 25°C. Thus in 10mL of water there will be 
gmg of acetanilide.
Na2CO3 + 2Cl- ⇒ 2NaCl + CO3^-2
<span>
1 mole of Na2CO3 = 106 g </span>
<span>2 moles of NaCl = 2 x 58.4
= 116.8 g
</span>Na2CO3 would increase by 116.8 / 106 = 1.10 to form 2NaCl.
<span>0.4862 g x 1.10 = 0.515 grams of NaCl.
</span>
K2CO3 + 2Cl- ⇒ 2KCl + CO3^-2
<span>1 mole of K2CO3 = 138.2 g </span>
<span>2 moles of KCl = 149.1 </span>
<span>
K2CO3 would increase by </span>149.1 /138.2 = 1.079 <span>to form 2KCl
</span>
<span> 0.4862 x 1.079 = 0.5246 g</span>
Answer:
GOOD MORNING DIDI be happy
Answer:
Option A - High frequency, short wavelength.
Explanation:
<em>If the sound is high then the frequency is also high but short-wavelength means lots of waves that always have a high pitch-sound and a high frequency. </em>
