Answer:
0°C.
Explanation:
Hello,
In this case, given the heating curve of water on the attached document, we can notice that at 0 °C the solid starts melting, which means that the melting point is reached. Melting point is known as a physical change whereby a solid changes to liquid by the addition of heat as it allows the molecules to separate to each other.
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Answer:
0.75 cal/g°c
Explanation:
for specific heat we have formula:
Amount of heat absorbed or released = mass x specific heat of a substance x change in temperature.
ΔQ=m x c x ΔT
where c= specific heat
m= mass of a substance
ΔT = total temperature
ΔQ = Amount of heat
so for specific heat,
c= ΔQ/mxΔT
c= 280/25x (25-10)
c= 280/375
c= 0.75 cal/g°c
140 g of nitrogen (N₂)
Explanation:
We have the following chemical equation:
N₂ + 3 H₂ -- > 2 NH₃
Now, to find the number of moles of ammonia we use the Avogadro's number:
if 1 mole of ammonia contains 6.022 × 10²³ molecules
then X moles of ammonia contains 6.022 × 10²⁴ molecules
X = (1 × 6.022 × 10²⁴) / 6.022 × 10²³
X = 10 moles of ammonia
Taking in account the chemical reaction we devise the following reasoning:
If 1 mole of nitrogen produces 2 moles of ammonia
then Y moles of nitrogen produces 10 moles of ammonia
Y = (1 × 10) / 2
Y = 5 moles of nitrogen
number of moles = mass / molecular weight
mass = number of moles × molecular weight
mass of nitrogen (N₂) = 5 × 28 = 140 g
Learn more about:
Avogadro's number
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Answer:
True
Explanation:
They are built from particles and blobs of congealed lava ejected from a single vent. As the gas-charged lava is blown violently into the air, it breaks into small fragments that solidify and fall as cinders around the vent to form a circular or oval cone, making them the simplest out there
Answer:
The correct option is B
Explanation:
The number of valence electron(s) increases across the period and thus influences the direction of periodic trend of electronegativity, electron affinity and ionization energy across the period. Thus, making option B the answer.
It should be noted that option A is wrong because elements in the same period generally have the same number of electron shells and thus the distance of this shells from the nucleus remains the same throughout the same period and thus option C is also wrong. Option D is wrong because the periodic trends have to do with chemical reactions which actually involves electrons and not protons.
