Answer:
19656J
Explanation:
Step 1:
Data obtained from the question.
Mass (M) = 78g
Initial temperature (T1) = 20°C
Final temperature (T2) = 80°C
Change in temperature (ΔT) = T2 – T1 =
80°C – 20°C = 60°C
Specific heat capacity (C) = 4.2J/g°C
Heat (Q) =...?
Step 2:
Determination of the heat required for the reaction.
Q = MCΔT
Q = 78 x 4.2 x 60
Q = 19656J
Therefore, 19656J of heat is required.
Answer:
Molar mass of solute is 183.4g/mol
Explanation:
Using Raoult's law it is possible to find moles of solute, thus:
Where pressure of solution is 53.15 mmHg, pressure of pure solvent is 54.68 mmHg and mole fraction is:
53.15 mmHg = X 54.68 mmHg
<em>0.9720 = X</em>
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Mole fraction of solvent is defined as moles of solvent / total moles.
Moles of solvent are:
286.8g × (1mol / 46.07g) = 6.225 moles of ethanol.
That is:
<em>Where Y are moles of solute.</em>
6.051 + 0.9720Y = 6.225
0.9720Y = 0.174
Y = 0.179 moles of solute
As mass of solute dissolved was 32.83g. Molar mass of solute is:
32.83g / 0.179mol = <em>183.4g/mol</em>
6.02 x 1023 atoms weigh out 63.55 grams copper.
No. of Molecules in water = 3.5mole x (6.02 x 10^23) molecules/mole = 2.107 x 10^24 molecules of H2O
Answer:
quantum mechanical model: A model of the atom that derives from the Schrödinger wave equation and deals with probabilities. wave function: Give only the probability of finding an electron at a given point around the nucleus. The quantum mechanical model of the atom also uses complex shapes of orbitals (sometimes called electron clouds), volumes of space in which there is likely to be an electron. So, this model is based on probability rather than certainty.
Fluorine.
Because:- Atoms want to become stable, for an atom to become stable, they need 8 valence electrons. Since Fluorine has 7 valence electrons, it only needs one more electron to become stable and have an octet. An octet is when an atom/element has 8 valence electrons. Since Fluorine will need to gain an electron, it will have a negative charge, and become an anion.
