Endothermic means it absorb energy from surrounding and its sign is positive so when it absorb this energy the flask or the container become colder
Ionic Bonding:
This type of bonding occurs when atoms want to fulfil their valence shells by taking/giving electrons to other atoms. This, leads to completed valence shells in most cases and ionisation of both elements. The opposite charges cause the elements to stick together because opposites attract.
Covalent Bonding:
This type of bonding occurs when electrons are shared between atoms to each fill up their own valence shells by sharing. The balance between the attraction forces and repulsion forces between the shared electrons is called covalent bonding.
Hope I helped :)
Answer:
The numerical value of K for the reaction is 2.36*10⁻⁴
Explanation:
A chemical equilibrium is a reaction that is never completed, since it occurs simultaneously in both directions (the reactants form products, and in turn, these form reactants again). In other words, it is a dynamic balance. When the concentrations of each of the substances involved (reactants or products) stabilize, that is, they are spent at the same rate as they are formed, chemical equilibrium is reached.
The equilibrium constant (Kc) is expressed as the ratio between the molar concentrations of reactants and products. Its value in a chemical reaction depends on the temperature, so this must always be specified.
Being:
aA + bB ⇄ cC + dD
then the constant Kc is:
![Kc=\frac{[C]^{c} *[D]^{d} }{[A]^{a} *[B]^{b} }](https://tex.z-dn.net/?f=Kc%3D%5Cfrac%7B%5BC%5D%5E%7Bc%7D%20%2A%5BD%5D%5E%7Bd%7D%20%7D%7B%5BA%5D%5E%7Ba%7D%20%2A%5BB%5D%5E%7Bb%7D%20%7D)
In the case of the reaction:
A₂(g) + 3 B₂(g) ⇒ 2 AB₃(g)
The constant Kc is:
![Kc=\frac{[AB_{3} ]^{2} }{[A_{2} ] *[B_{2} ]^{3} }](https://tex.z-dn.net/?f=Kc%3D%5Cfrac%7B%5BAB_%7B3%7D%20%5D%5E%7B2%7D%20%7D%7B%5BA_%7B2%7D%20%5D%20%2A%5BB_%7B2%7D%20%5D%5E%7B3%7D%20%7D)
Being:
- [AB₃]=7.6*10⁻⁴
- [A₂]= 0.0055
- [B₂]= 0.763
and replacing, you get:
![Kc=\frac{(7.6*10^{-4} )^{2} }{0.0055 *(0.763)^{3} }](https://tex.z-dn.net/?f=Kc%3D%5Cfrac%7B%287.6%2A10%5E%7B-4%7D%20%29%5E%7B2%7D%20%7D%7B0.0055%20%2A%280.763%29%5E%7B3%7D%20%7D)
Kc=2.36*10⁻⁴
<u><em>The numerical value of K for the reaction is 2.36*10⁻⁴</em></u>
The exact molecular mass for butane (C4H10) is
12.0096*4+1.0079*10=58.1174 which is 58.1 to 3 significant figures.
Proportion of carbon in the compound
12.0096*4: 58.1174
=>
48.0384 : 58.1174
The mass of carbon in 2.50 grams of butane can be obtained by proportion, namely
Mass of carbon
= 2.50 * (48.0384/58.1174)
= 2.0664
= 2.07 g (approximated to 3 significant figures)
Answer:
it's A endothermic its when two objects rub each other to form heat this is also known as friction force