Answer:
The correct option is;
D. (2)(56 g)
Explanation:
MgCl₂ + 2KOH → Mg(OH)₂ + 2KCl
From the balanced chemical reaction equation, we have;
One mole of MgCl₂ reacts with two moles of KOH to produce one mole of Mg(OH)₂ and 2 moles of KCl
Therefore, the number of moles of KOH that react with one mole of KCl = 2 moles
The mass, m, of the two moles of KOH = Number of moles of KOH × Molar mass of KOH
The molar mass of KOH = 56.1056 g/mol
∴ The mass, m, of the two moles of KOH = 2 moles × 56.1056 g/mol = 112.2112 grams
The amount in grams of KOH that react with one mole of MgCl₂ = 112.2112 grams ≈ 112 grams = (2)(56 g).
Answer:
Empirical formula: BH3
Molecular Formula: B2H6
Explanation:
To solve the exercise, we need to know how many boron atoms and how many hydrogen atoms the compound has. We know that of the total weight of the compound, 78.14% correspond to boron and 21.86% to hydrogen. As the weight of the compound is between 27 g and 28 g, using the above percentages we can solve that the compound has between 21.1 g and 21.8 g of boron, and between 5.9 g and 6.1 g of hydrogen:
100% _____ 27 g
78.14% _____ x = 78.14% * 27g / 100% = 21.1 g boron
100% ______27 g
21.86% ______ x = 21.86% * 27g / 100% = 5.9 g hydrogen
100% _____ 28 g
78.14% _____ x = 78.14% * 28g / 100% = 21.8 g boron
100% _____ 28g
21.86% _____ x = 21.86% * 28g / 100% = 6.1 g hydrogen
So, if the atomic weight of boron is 10.8 g, there must be two boron atoms in the compound that sum 21.6 g. The weight of hydrogen is 1 g, so the compound must have six hydrogen atoms.
The molecular formula represents the real amount of atoms that form a compound. Therefore, the molecular formula of the compound is B2H6.
The empirical formula is the minimum expression that represents the proportion of atoms in a compound. For example, ethane has 2 carbon atoms and 6 hydrogen atoms, so its molecular formula is C2H6, however, its empirical formula is CH3. Therefore, the empirical formula of the boron compound is BH3.
Answer:
See the answer below
Explanation:
<em>Since the experiment is set out to determine the melting point of the white solid, after missing the melting point due to distraction, there are two possible solutions and both involves a repeat of the experiment.</em>
1. The first one is to allow the molten substance to solidify again and then repeat the experiment. This time around, a critical attention should be paid to be able to notice the melting point temperature once the temperature gets to 132 C.
2. The second solution would be discard the molten substance and repeat the experiment with the a new solid one. Similarly, critical attention should be paid once the temperature gets to 132 C since it is sure that the melting point lies within 132 and 138 C.
Answer:
The given substance is cast iron.
Explanation:
Given data:
Mass of substance = 50 g
Heat absorbed = 23000 J
Initial temperature = 250°C
Final temperature = 1250°C
Which metal is this = ?
Solution:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 1250°C - 250°C
ΔT = 1000°C
23000 j = 50 g ×c ×1000 °C
23000 J = 50,000 g. °C×c
c = 23000 J /50,000 g. °C
c = 0.46 J/g.°C
The given substance is cast iron.
Answer: c
Herbivore that feeds on primary consumers
Explanation:
