Answer:
81°C.
Justification:
We can arrive at this conclusion using the formula:
Q = m.c.ΔT,
where Q denotes the heat lost by water (Q = - 1200 J).
m represents the mass of water (m = 20.0 g).
c indicates the specific heat of water (c = 4.186 J/g.°C).
ΔT signifies the difference between the starting temperature and the final temperature (ΔT = final T - initial T = final T - 95.0°C).
Given Q = m.c.ΔT
It follows that (- 1200 J) = (20.0 g)(4.186 J/g.°C)(final T - 95.0°C ).
(- 1200 J) = 83.72 final T - 7953.
∴ final T = (- 1200 J + 7953)/83.72 = 80.67°C ≅ 81.0°C.
Consequently, the correct answer is: 81°C.
Different wavelengths are involved.
Explanation:
When magnesium ignites with a bright white flame, it indicates that various wavelengths are related to the electron transitions occurring in the magnesium atom.
- Upon combustion, the electrons within the atom become excited.
- They emit characteristic light that corresponds to their energy levels.
- White light consists of a mix of different wavelengths.
- Seeing white light implies that multiple wavelengths combined are responsible for the observed emission.
Learn more:
Spectrum
Answer:
Explanation:
In KCl, the two elements that combine to create KCl are potassium (K) and chlorine (Cl).
Potassium, as a Group 1 element, possesses one valence electron in its outermost shell which it readily donates during bonding. Every element aims to achieve a stable electron configuration, typically with 2 or 8 electrons in its outer shell. Potassium is characterized by its lower electronegativity and higher ionization energy, making it more likely to donate its electron than to accept one. On the other hand, chlorine belongs to Group 17 and has 7 electrons in its outer shell, requiring just one additional electron to complete its octet. Chlorine’s higher electronegativity and lower ionization energy facilitate its tendency to accept an electron rather than donate it.
The bond between potassium and chlorine that results in KCl is termed an electrovalent bond.
Reaction equation:
K + Cl → KCl
Response: The moles in 369 grams of calcium hydroxide are 4.98 moles
Reasoning: Given,
Mass of calcium hydroxide = 369 g
Molar mass of calcium hydroxide = 74.093 g/mole
Formula used:
Now substituting the provided values into this formula, you will find the moles of calcium hydroxide.
Thus, the number of moles in 369 grams of calcium hydroxide is, 4.98 moles
