2 NaOH (s) + CO₂ (g) → Na₂CO₃ (s) + H₂O (l)
Explanation:
The most probably chemical reaction is:
2 NaOH (s) + CO₂ (g) → Na₂CO₃ (s) + H₂O (l)
Sodium Hydroxide (solid) + Carbon Dioxide (gas) → Sodium Carbonate (solid) + Water (gas)
In this reaction the water you obtain have to be in liquid form because the reaction takes place at room temperature. However because the student left the beaker for 24 hours, the water have a plenty of time to evaporate, so in the end only sodium carbonate (Na₂CO₃) remained in the beaker.
number of moles = mass / molar weight
number of moles of NaOH = 0.4 / 40 = 0.01 moles
Taking in account the chemical reaction, we devise the following reasoning:
if 2 moles of NaOH produce 1 mole of Na₂CO₃
then 0.01 moles of NaOH produce X mole of Na₂CO₃
X = (0.01 × 1) / 2 = 0.005 moles of Na₂CO₃
mass = number of moles × molar weight
mass of Na₂CO₃ = 0.005 × 106 = 0.53 g
mass of Na₂CO₃ = mass of beaker and its contents after 24h - mass of empty beaker
mass of Na₂CO₃ = 113.09 - 112.58 = 0.51 g which is close the theoretical value of 0.53 g.
Learn more about:
number of moles
#learnwithBrainly
b. It is a reaction that requires heat to proceed.
c. It is a reaction that draws heat from its surroundings.
d. It is a reaction that releases heat to its surroundings.
True
False
Answer:
1)conduction
2) convection
3) conduction
4) radiation
5) radiation
6) radiation
7) conduction
8) conduction
9) radiation
10) convection
Explanation:
not 100% sure
1) The binding energy per nucleon is 7.59 MeV/nucleon and 2) The binding energy per nucleon is 8.39 MeV/nucleon.
1) The binding energy per nucleon is as follows:
m_proton + m_neutron + m_electron - m_U
= 92*1.007276466812 + 92*5.4857990943e-4 + 143*1.008664916 - (235.0439299)
= 1.9151 u
= 931.494061 * 1.9151 MeV
= 1784 MeV
= 1784/235 = 7.59 MeV/nucleon
2) The binding energy per nucleon is as follows:
m_proton + m_neutron + m_electron - m_Cs
= 55*1.007276466812 + 55*5.4857990943e-4 + 82*1.008664916 - (136.9070895)
= 1.2338 u
= 931.494061 * 1.2338 MeV
= 1149 MeV
=1145/137 = 8.39 MeV/nucleon
To learn more about binding energy check the link below:
#SPJ4
The correct option for above statement is:
B.Joseph Proust
Explanation:
Joseph Proust printed his Law of Definite Proportions (or Law of Constant Composition) in 1794. This law states that a compound consists of exact proportions of parts by mass no matter however the compound was created.
B. 4,000 g
C. 40 g
D. 4,000 cg