Answer:
d. Sum of product enthalpies minus the sum of reactant enthalpies
Explanation:
The standard enthalpy change of a reaction (ΔH°rxn) can be calculated using the following expression:
ΔH°rxn = ∑n(products) × ΔH°f(products) - ∑n(reactants) × ΔH°f(reactants)
where,
ni are the moles of products and reactants
ΔH°f(i) are the standard enthalpies of formation of products and reactants
Answer: all elements in the periodic table is classified as elements
Explanation:
The structure of the table shows periodic trends. The seven rows of the table, called periods, generally have metals on the left and nonmetals on the right. The columns, called groups, contain elements with similar chemical behaviours. Six groups have accepted names as well as assigned numbers: for example, group 17 elements are the halogens; and group 18 are the noble gases
Answer:
0.185moles
Explanation:
Given parameters:
Volume of O₂ = 49.8L
Unknown:
Number of moles of sucrose required = ?
Solution:
We can assume that the reaction takes place at standard temperature and pressure.
From this, we can find the number of moles of oxygen that reacted and extrapolate to that of sucrose.
Chemical equation;
C₁₂H₂₂0₁₁ + 120₂ → 12CO₂ + 11H₂0
Number moles =
at STP
Number of moles of oxygen gas =
= 2.22moles
12 moles of oxygen gas combines with 1 mole of sucrose
2.22 moles of oxygen gas will combine with
= 0.185moles
The melting point of potassium = 
Melting point of titanium = 
Titanium has a stronger metallic bonding compared to potassium. Titanium being a transition metal has greater number of valence electrons (4 valence electrons) contributing to the valence electron sea compared to potassium which has only one valence electron. The atomic size of Titanium much lower than that of potassium, so the bonding between Titanium atoms is stronger than that of potassium. Hence, the melting point of Titanium is much higher than that of potassium.