The second option - electrons are the subatomic particles with the smallest mass.
Both protons and electrons have charge (protons are positive and electrons are negative)
Protons and neutrons both equal 1 amu (atomic mass unit), whereas electrons weigh about 1/1000 amu
Electrons orbit around the nucleus, whereas protons and neutrons are inside of the nucleus
And for the last option, I already answered it
Answer:
2.11 g hydrobromic acid (correct to 3SF)
Explanation:
Molecular formula of hydrobromic acid = C2H5BrO2
mass of C2H5BrO2 = 140.96g
Beginning with what we're given, 9.03*10^21 we then make a conversion by using Avegadro's number which is 6.02*10^23 per mole (Oct. 23 at 6:02 am is national mole day :) Then, we need to convert out of moles, 140.96g hydrombromic acid per mole.
It looks like this:
9.03*10^21 molecules • (1 mol C2H5BrO2 / 6.02*10^23 molecules) • (140g C2H5BrO2 / 1 mol) = 2.1144 g C2H5BrO2
The volume of the 0.15 M LiOH solution required to react with 50 mL of 0.4 M HCOOH to the equivalence point is 133.3 mL
<h3>Balanced equation </h3>
HCOOH + LiOH —> HCOOLi + H₂O
From the balanced equation above,
The mole ratio of the acid, HCOOH (nA) = 1
The mole ratio of the base, LiOH (nB) = 1
<h3>How to determine the volume of LiOH </h3>
- Molarity of acid, HCOOH (Ma) = 0.4 M
- Volume of acid, HCOOH (Va) = 50 mL
- Molarity of base, LiOH (Mb) = 0.15 M
- Volume of base, LiOH (Vb) =?
MaVa / MbVb = nA / nB
(0.4 × 50) / (0.15 × Vb) = 1
20 / (0.15 × Vb) = 1
Cross multiply
0.15 × Vb = 20
Divide both side by 0.15
Vb = 20 / 0.15
Vb = 133.3 mL
Thus, the volume of the LiOH solution needed is 133.3 mL
Learn more about titration:
brainly.com/question/14356286
Answer:
5.82 ×10⁴ j
Explanation:
Given data:
Mass of water = 25.7 g
Amount of heat to evaporate it = ?
Molar heat of vaporization = 4.07×10⁴ j/mol
Solution:
First of all we will calculate the number of moles of water.
Number of moles = mass/ molar mass
Number of moles = 25.7 g/ 18 g/mol
Number of moles = 1.43 mol
Energy needed for one mole is 4.07×10⁴ j.
For 1.43 mol:
1.43 mol × 4.07×10⁴ j/ 1mol
5.82 ×10⁴ j
Answer:
1 L
Explanation:
ppm means parts per million. Generally the relationship between mass and litre is given as;
1 ppm = 1 mg/L
This means that 1 ppm is equivalent to 1 mg of a substance dissolved in 1 L of water.
