Answer:
B
Explanation:
Dalton worked with mainly about the chemistry of atoms.
how do atoms combine to form various molecules.
—rather than the details of the physical, internal structure of atoms, although he never denied the possibility of atoms' having a substructure.
The volume of 0.160 m Li2S solution required to completely react with 130 ml of 0.160 CO(NO3)2 is calculated as below
write the reacting equation
Co(NO3)2 + Li2S = 2LiNO3 + COS
find the moles of CO(NO3)2 = molarity x volume
= 130 ml x 0.160=20.8 moles
since the reacting moles between CO(NO3)2 to LiS is 1:1 the moles of LiS is also 20.8 moles
volume of Lis is therefore = moles of Lis/ molarity of LiS
= 20.8/0.160 = 130 Ml
The reaction for magnesium iodide when put into water is as below
MgI2(s) → Mg^2+(aq) + 2I^-(aq)
when magnesium iodide but into water it dissociate/ ionize completely into Mg^2+ and 2l^- ions. Magnesium iodide dissociate/ionize completely because magnesium iodide is a strong electrolyte which dissociate/ ionize completely into their ions when it is put into water .
Answer:
The total heat required is 691,026.36 J
Explanation:
Latent heat is the amount of heat that a body receives or gives to produce a phase change. It is calculated as: Q = m. L
Where Q: amount of heat, m: mass and L: latent heat
On the other hand, sensible heat is the amount of heat that a body can receive or give up due to a change in temperature. Its calculation is through the expression:
Q = c * m * ΔT
where Q is the heat exchanged by a body of mass m, constituted by a substance of specific heat c and where ΔT is the change in temperature (Tfinal - Tinitial).
In this case, the total heat required is calculated as:
- Q for liquid water. This is, raise 248 g of liquid water from O to 100 Celsius. So you calculate the sensible heat of water from temperature 0 °C to 100° C
Q= c*m*ΔT
Q=103,763.2 J
- Q for phase change from liquid to steam. For this, you calculate the latent heat with the heat of vaporization being 40 and being 248 g = 13.78 moles (the molar mass of water being 18 g / mol, then )
Q= m*L
Q=562.0862 kJ= 562,086.2 J (being 1 kJ=1,000 J)
- Q for temperature change from 100.0
∘
C to 154
∘
C, this is, the sensible heat of steam from 100 °C to 154°C.
Q= c*m*ΔT
Q=25,176.96 J
So, total heat= 103,763.2 J + 562,086.2 J + 25,176.96 J= 691,026.36 J
<u><em>The total heat required is 691,026.36 J</em></u>
Answer:
Chopping wood logs
A pot of water o a grate over a burning fire
Explanation:
Physical change is easily reversible. Burning/combustion is a chemical process where substances react rapidly with oxygen: this is usually irreversible.
The marshmallow, roasted food and burned wood all undergo combustion and hence are tagged chemical changes.
Explanation: