Answer:
See explanation
Explanation:
The reaction occurs as follows;
KBr(aq) + AgNO3(aq) ----> AgBr(s) + KNO3(aq)
Number of moles of AgBr formed = mass /molar mass =1.740 g/187.77 g/mol = 0.0093 moles
From the reaction equation;
1 mole of KBr yields 1 mole of AgBr
Hence the number of moles of KBr reacted = 0.0093 moles
Mass of KBr present = 0.0093 moles × 119g/mol = 1.11 g
Mass of KNO3 = 2.850 g - 1.11 g = 1.74 g
Percentage of KBr = 1.11 g/2.850 g × 100 = 38.9%
Percentage of KNO3 = 1.74 g/2.850 g × 100 = 61.1%
Answer:
The time required to melt the frost is 3.25 hours.
Explanation:
The time required to melt the frost dependes on the latent heat of the frost and the amount of heat it is transfered by convection to the air .
The heat transferred per unit area can be expressed as:
being hc the convective heat transfer coefficient (2 Wm^-2K^-1) and ΔT the difference of temperature (20-0=20 °C or K).
If we take 1 m^2 of ice, with 2 mm of thickness, we have this volume
The mass of the frost can be estimated as
Then, the amount of heat needed to melt this surface (1 m²) of frost is
The time needed to melt the frost can be calculated as
It's your hw so you really should understand it so you dont have to ask for help so I'll try to explain it the best I can.
1.SD (only one switch occurs, between fluorine and bromide)
2.DD (two things are switched, sulfate and nitrate)
3. D (One compound is broken up into smaller compounds)
4.C (The products of combustion are always h20 and co2)
5.DD (again, two things are switched, bromide and nitrate)
6.SD (In SDR, look for a lone molecule reacting with a compound)
7.S (two smaller compounds become one big compound)
8. D( A big compound is broken up)
9. DD (I think Its DD because two molecules were displaced)*not sure
10.DD(two molecules are displaced, phosphate and hydroxide)
Answer:
A. Biomass
Explanation:
Biomass must be burned to be useful as a fuel.
The combustion of biomass produces carbon dioxide, which is a greenhouse gas.
B, C, and C are wrong. Once these energy sources are built, they produce no greenhouse gases.
Answer: Filtration
Explanation:
Heterogeneous mixtures : It is a mixture that has non-uniform composition throughout the solution and the particle size or shapes are also different. There is a physical boundary between the dispersed phase and dispersion medium.
Homogeneous mixtures : It is a mixture that has uniform composition throughout the solution and the particle size or shapes are not different. There is no physical boundary between the dispersed phase and dispersion medium.
Filtration is a type of mechanical separation process in which the smaller particles are separated from the bigger particles through the filter paper where small particles pass through the fine holes of filter paper and the left ones remain on the filter paper.