Answer: hello the complete question is attached below
Visibility of molecular ion = m/z value of 77
Explanation:
For The molecular ion to be visible, it has to be at an m/z value of 77 and this is because molecular ions will have an m/z ratio = molecular mass of given molecule in most cases but not always in all cases.
And the visibility is possible after the removal of CH₃ ion.
ii) Evidence in the mass spectrum that suggests peak at m/z = 77
attached below
Answer: 1.85M
Explanation:
Sodium hydroxide has a chemical formula of NaOH
Given that,
Amount of moles of NaOH (n) = ?
Mass of NaOH in grams = 63g
For molar mass of NaOH, use the molar masses:
Sodium, Na = 23g;
Oxygen, O = 16g;
Hydrogen, H = 1g
NaOH = (23g + 16g + 1g)
= 40g/mol
Since, amount of moles = mass in grams / molar mass
n = 63g / 40.0g/mol
n = 1.575 mole
Volume of NaOH solution (v) = 850mL
[Convert 850mL to liters
If 1000mL = 1L
850mL = 850/1000 = 0.85L]
Concentration of NaOH solution (c) = ?
Since concentration (c) is obtained by dividing the amount of solute dissolved by the volume of solvent, hence
c = n / v
c = 1.575 mole / 0.85L
c = 1.85M [1.85M is the concentration in moles per litres which is also known as molarity]
Thus, the molarity of the solution is 1.85M
Answer:
2666.7 hours
Explanation:
The key to solve this problem is that we are given the propane gas consumed in one hour by giving us the information of the volume consumed at 1 atm, 298 K (25 +273). Using the gas law we can calculate the rate of consumption of propane per hour, and from here we can calculate its mass and converting it to gallons and finally diving the 400 gallos by this number.
PV = nRT ∴ n = PV/RT
n = 1 atm x 165 L/ (0.08206 Latm/kmol x 298 K ) = 6.75 mol propane
Mass propane :
6.75 mol x 44 g/mol = 296.88 g
convert this to Kg:
296.88 g/ 1000 g/Kg = 0.30 Kg
calculate the volume in liters this represents by dividing by the density:
0.30 Kg / 0.5077 Kg/L = 0.59 L
changing this to gallons
0.59 L x 1 gallon/3.785 L = 0.15 gallon
and finally calculate how many hours the 400 gallons propane tank will deliver
400 gallon/ 0.15 gallon/hr = 2666.7 hr
<u><em>THEY ARE NOT AFFECTED BY EARTH`S ATMOSPHERE</em></u>
Answer:
C. Their properties change completely.
Explanation:
The electron configurations of the elements show a periodic variation with increasing atomic number. Consequently, there are also periodic variations in physical and chemical behavior.
When atoms interact to form a chemical bond, they combine in order to <u>achieve a more stable electron configuration.</u> As a consequence, the compounds formed exhibit completely different properties.
For example, when solid magnesium burns in air, it forms both magnesium oxide and magnesium nitride, which are gases.
