Answer:
1. Density can be used to identify a substance
2. Density can be used to ascertain whether a substance will float in water.
Explanation:
The calculation of the density of a substance can be used to identify the substance. If the density of a substance is calculated accurately, and compared with a table of standard densities, then we can identify that substance.
Also, density determines whether an object will float or sink in water. If an object is less dense than water then it will float in water. If it is denser than water, then it will sink in water.
Answer:
S(metal) = 0.66J/g°C
Explanation:
We can find specific heat of a material, S, using the equation:
q = m*S*ΔT
<em>Where q is change in heat, m is the mass of the substance, S specific heat and ΔT change in temperature.</em>
The heat given by the metal is equal to the heat that water absorbs, that is:
m(Metal)*S(metal)*ΔT(Metal) = m(Water)*S(water)*ΔT(water)
<em>Where:</em>
m(Metal) = 76.0g
S(metal) = ?
ΔT(Metal) = 96.0°C-31.0°C = 65.0°C
m(Water) = 120.0g
S(water) = 4.184J/g°C
ΔT(water) = 31.0°C-24.5°C = 6.5°C
Replacing:
76.0g*S(metal)*65.0°C = 120.0g*4.184J/g°C*6.5°C
S(metal) = 0.66J/g°C
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The law of conservation applies because the energy is not been created or destroyed. The energy that the metal gives is absorbed by the water.
I think the answer is 4 carbon dioxide
The equation of 5m+4=7m+6 is equal to m=-1
Answer:
The ΔH is 5.5 kJ/mol and the reaction is endothermic.
Explanation:
To calculate the ∆H (heat of reaction) of the combustion reaction, that is, the heat that accompanies the entire reaction, you must make the total sum of all the heats of the products and of the reagents affected by their stoichiometric coefficient ( number of molecules of each compound participating in the reaction) and finally subtract them:
Combustion enthalpy = ΔH = ∑H products - ∑Hreactants
In this case:
ΔH = 15.7 kJ/mol - 10.2 kJ/mol= 5.5 kJ/mol
An endothermic reaction is one whose enthalpy value is positive, that is, the system absorbs heat from the environment (ΔH> 0).
<u><em>The ΔH is 5.5 kJ/mol and the reaction is endothermic.</em></u>
