Answer:
3 × 10⁴ kJ
Explanation:
Step 1: Write the balanced thermochemical equation
C₃H₈(g) + 5 O₂(g) ⟶ 3 CO₂(g) + 4 H₂O(g) ΔH = -2220 kJ
Step 2: Calculate the moles corresponding to 865.9 g of H₂O
The molar mass of H₂O is 18.02 g/mol.
865.9 g × 1 mol/18.02 g = 48.05 mol
Step 3: Calculate the heat produced when 48.05 moles of H₂O are produced
According to the thermochemical equation, 2220 kJ of heat are evolved when 4 moles of H₂O are produced.
48.05 mol × 2220 kJ/4 mol = 2.667 × 10⁴ kJ ≈ 3 × 10⁴ kJ
Answer : The oxidation state of Mg in Mg(s) is (0).
Explanation :
Oxidation number or oxidation state : It represent the number of electrons lost or gained by the atoms of an element in a compound.
Oxidation numbers are generally written with the sign (+) and (-) first and then the magnitude.
Rules for Oxidation Numbers are :
The oxidation number of a free element is always zero.
The oxidation number of a monatomic ion equals the charge of the ion.
The oxidation number of Hydrogen (H) is +1, but it is -1 in when combined with less electronegative elements.
The oxidation number of oxygen (O) in compounds is usually -2.
The oxidation number of a Group 17 element in a binary compound is -1.
The sum of the oxidation numbers of all of the atoms in a neutral compound is zero.
The sum of the oxidation numbers in a polyatomic ion is equal to the charge of the ion.
The given chemical reaction is:
In the given reaction, the oxidation state of Mg in Mg(s) is (0) because it is a free element and the oxidation state of Mg in 
is (+2).
Hence, the oxidation state of Mg in Mg(s) is (0).
Answer:
SI
modern form of the metric system
Explanation:
The scientific instruments used to heat water to 85 degree Celsius has been graduated cylinder, beaker, thermometer, and hot plate. Thus, option B is correct.
Scientific equipments have been defined as the instruments and glassware that has been used in the scientific study and experimentation.
<h3>Equipments for heating the water</h3>
The water has been heated to the temperature of 85 degrees Celsius. The temperature has to be monitored thus, a thermometer has been used.
The water has been measured to be 1 L, thus the graduated cylinder, and beaker has been used for the measurement and heating of water.
The heat has been provided to the beaker by placing it on a hot plate.
Thus, the scientific instruments used to heat water to 85 degree Celsius has been graduated cylinder, beaker, thermometer, and hot plate. Thus, option B is correct.
Learn more about scientific equipments, here:
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