Answer:
1280J are required.
Explanation:
Heat of fusion is defined as the amount of heat required to change its state from liquid to solid at its melting point at constant pressure.
As heat of fusion of gold is 64J/g, there are required 64J to melt 1g of gold at its melting point. The energy required to melt 20g is:
20g * (64J/g) =
1280J are required
Answer:
the answer is 11
Explanation:
Ok, let us understand what is an atomic number, an atomic number is simply the proton number, the atomic number is always seen at the bottom left corner in a element of a periodic table, it is the number of proton in a atom of a certain element.
Fe(NO3)2=0
Fe+2(+3+3*-2)=0
Fe+2*-3=0
Fe=-(-6)
Fe=+6
So, Fe=+6, N=+3, O=-2
Answer:
0.210 M
Explanation:
<em>A 75.0 mL aliquot of a 1.70 M solution is diluted to a total volume of 278 mL.</em>
In order to find out the resulting concentration (C₂) we will use the dilution rule.
C₁ × V₁ = C₂ × V₂
1.70 M × 75.0 mL = C₂ × 278 mL
C₂ = 0.459 M
<em>A 139 mL portion of that solution is diluted by adding 165 mL of water. What is the final concentration? Assume the volumes are additive.</em>
Since the volumes are additive, the final volume V₂ is 139 mL + 165 mL = 304 mL. Next, we can use the dilution rule.
C₁ × V₁ = C₂ × V₂
0.459 M × 139 mL = C₂ × 304 mL
C₂ = 0.210 M
