Answer:
Cs
Explanation:
Metallic character increases across a period to the left and downwards.
If you look at the periodic table, Cs is lower and more towards the left.
Answer:
independent variable- instrumental music
dependent variable- Number of stacks of papers made
experimental variable- Group A has instrumental music
playing
constant- same task,
Explanation:
Answer:
(a) 282 kJ
(b) 67.4 Calories
Explanation:
(a) The molar enthalpy, ΔH = −2802.5 kJ/mol, means that the heat produced by the reaction is 2802.5 kJ per mol of glucose.
We can multiply the enthalpy by the number of moles of glucose to get the heat produced by the metabolism. Grams of glucose will be converted to moles using the molar mass of glucose (180.156 g/mol):
(18.1 g)(mol/180.156g)(2802.5 kJ/mol) = 282 kJ
(b) Using the result we obtained above, kJ will be converted to Calories using the conversion factor of 4.184J = 1 cal. Calorie with a capital C is the same as a kilocalorie.
(282 kJ)(1 cal/4.184J) = 67.4 kcal = 67.4 Calories
Answer:
84.11 g/mol
Explanation:
A metal from group 2A will form the cation M²⁺, and the ion carbonate is CO₃²⁻, so the metal carbonate must be: MCO₃, and the reaction:
MCO₃(s) → MO(s) + CO₂(g)
For the stoichiometry of the reaction, 1 mol of MCO₃(s) will produce 1 mol of CO₂. Using the ideal gas law, it's possible to calculate the number of moles of CO₂:
PV = nRT , where P is the pressure, V is the volume(0.285 L), R is the gas constant (62.36 mmHg*L/mol*K), n is the number of moles, and T is the temperature (25 + 273 = 298 K).
69.8*0.285 = n*62.36*298
18583.28n = 19.893
n = 0.00107 mol
So, the number of moles of the metal carbonate is 0.00107. The molar mass is the mass divided by the number of moles:
0.0900/0.00107 = 84.11 g/mol
