Answer:
We need 1.1 grams of Mg
Explanation:
Step 1: Data given
Volume of water = 78 mL
Initial temperature = 29 °C
Final temperature = 78 °C
The standard heats of formation
−285.8 kJ/mol H2O(l)
−924.54 kJ/mol Mg(OH)2(s)
Step 2: The equation
The heat is produced by the following reaction:
Mg(s)+2H2O(l)→Mg(OH)2(s)+H2(g)
Step 3: Calculate the mass of Mg needed
Using the standard heats of formation:
−285.8 kJ/mol H2O(l)
−924.54 kJ/mol Mg(OH)2(s)
Mg(s) + 2 H2O(l) → Mg(OH)2(s) + H2(g)
−924.54 kJ − (2 * −285.8 kJ) = −352.94 kJ/mol Mg
(4.184 J/g·°C) * (78 g) * (78 - 29)°C = 15991.248 J required
(15991.248 J) / (352940 J/mol Mg) * (24.3 g Mg/mol) = 1.1 g Mg
We need 1.1 grams of Mg
Answer:
Metals have an important role in our daily life. The discovery of the metal is said to be the most important milestone in the history of human civilization. We cannot live without machines now. All machines are made up of metals. Machines reduce the work of man. Many modern facilities would not have been possible without metals. Most metals occur as their compounds in nature.
Answer:
5.8 g
Explanation:
Molecular weight in Daltons is equivalent to the molecular weight in grams per mole.
The amount of NaCl required is calculated as follows:
(2 mol/L)(50 mL)(1 L/1000 mL) = 0.1 mol
This amount is converted to grams using the molar mass (58 g/mol).
(0.1 mol)(58 g/mol) = 5.8 g
Cross-section of a metal wire wrapped in plastic insulation the metal wire is an element.
<h3>What is an element?</h3>
An element is a substance or material that cannot be affected by an external substance or cannot be broken down by any reaction.
Metal wire is serving as an element, it should not be easily broken or penetrated as an insulator.
Therefore, Cross-section of a metal wire wrapped in plastic insulation the metal wire is an element.
Learn more on element here,
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