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
12 % salt is present in 125 g mixture of salt and sand.
Keep in mind that the total percentage is always 100 %
Therefore, if 12 % is the salt, remaining 88 % must be
sand.
a. The amount of mixture is 125 q. Here, 12 % of 125 is
12 * 125 / 100 = 15 g of salt is present in 125 g mixture.
b. The amount of sand can be calculated similarly, 88 %
of 125 g is 88 * 125 / 100 = 110 g of sand is present in
125 g mixture.
Answer:
2KCl + F₂ → 2KF + Cl₂
Explanation:
Law of conservation of mass:
According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
This law was given by French chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
2KCl + F₂ → 2KF + Cl₂
In this equation mass of reactant and product is equal. There are 2 potassium 2 chlorine and fluorine atoms on both side of equation it means mass remain conserved.
All other options are incorrect because mass is not conserved.
Mg₂ + LiBr ---> LiMg + Br
In this equation mass of magnesium is more on reactant side.
Na +O₂ ---> Na₂O
In this equation there is more oxygen and less sodium on reactant side while there is more sodium and less oxygen on product side.
H₂O ---> H₂ + O₂
In this equation there is less oxygen on reactant side while more oxygen on product side.
In HCl-HCl, the hydrogen-chlorine link is a polar covalent bond. It is produced when two atoms share an electron pair.
When atoms with various electronegativities share electrons in a covalent link, the result is a polar covalent bond. Think about the molecule of hydrogen chloride (HCl). In order to generate an inert gas electron configuration, each atom of HCl needs an additional electron. Despite having a stronger electronegativity than hydrogen, the chlorine atom cannot remove an electron from hydrogen due to its inability to attract electrons. As a result, a polar covalent bond in hydrogen chloride has an unbalanced distribution of bonding electrons.
Learn more about electronegativity here-
brainly.com/question/17762711
#SPJ4
C is the answer because he wants to know if less force is needed to pull on a slippery surface which reduces friction
