Gram The Moon was once much doser to E ffect do you think that this distance had What on eclipses?

4.Calculate the Hydroxide, Hydrogen ion and POH of solution if the PH of solution is 7.b

trapecia [35]

the ph is gonna be your value and the 4 is gonna be your main subject

so as the ph is your value u gonna ad your ph and 7 and 4 toghter then multiple your answer 2 times because ph represent multiple and your value

3 0

3 years ago

Calculate the concentration of all species in a 0.165 m solution of h2co3.

xxMikexx [17]

(1) H2CO3 + H2O --> HCO3- + H3O+ [Ka = 4.5E-7]

(2) HCO3- + H2O --> CO32- + H3O+ [Ka = 4.7E-11]

Observe that the two Ka values differ from each other drastically. This will mean that in terms of pH, ONLY THE FIRST IONIZATION WILL AFFECT pH.

(1) H2CO3 + H2O --> HCO3- + H3O+ [Ka = 4.5E-7]

I.....0.165M..................0..........

C......-x......................+x........

E....0.165-x.................x...........

4.5E-7 = x^2/(0.165-x) <-- use the appoximation rule because Ka is very small

2.72E-4 = x

Thus, from equation (1), we see that the [H3O+] = 2.72E-4M, [H2CO3] = 0.165M, and [HCO3-]= 2.72E-4M. Note that THIS step will determine the pH of the polyprotic acid

To calculate the last species, just transfer these values the next equation

(2) HCO3- + H2O --> CO32- + H3O+ [Ka = 4.7E-11]

I....2.72E-4..................0..........

C

E

4.7E-11 = (x*2.72E-4)/2.72E-4

4.7E-11 = x = [CO32-]

To calculate the OH- from H3O+, just find the pH of H3O+, subtract it from 14 to find the pOH, and find the [OH-] from that.

3 0

3 years ago

Sodium metal reacts with water to produce hydrogen gas.

ad-work [718]

Answer:

Q1. D) A single replacement reaction takes place because sodium is more reactive than hydrogen.

Explanation: $2Na+2H_2O\rightarrow 2NaOH+H_2$ Sodium metal reacts with water to givesodium hydroxide and hydrogen gas. A single replacement reaction takes place because sodium is more reactive than hydrogen.

Sodium easily lose electrons than hydrogen and get oxidized to $Na^+$ and $H^+$ get reduced to give $H_2$ .

Q2. B) It is a single replacement reaction, and the cations in the two ionic compounds are different.

Explanation: $3Na+AlCl_3\rightarrow 3NaCl+Al$ where Sodium is a metal and $AlCl_3$ is an ionic compound. Na being more reactive than Al, displaces it from its salt solution.

Q3. D) $Zn+H_2SO_4\rightarrow ZnSO_4+H_2$

Explanation: A single replacement reaction is one in which a more reactive element displaces a less reactive element from its salt solution.Thus zinc can easily lose electrons as compared to hydrogen and result in the formation of zinc sulfate and hydrogen.

Q4. False

$Zn+CaCl_2\rightarrow$ no reaction

Explanation: As zinc lies lower in reactivity series, it is less reactive than calcium. It will not be able to displace calcium from its salt and hence no reaction occur. Thus the given statement is false.

Q5. False

Explanation: A double displacement reaction is one in which exchange of ions take place. Thus an element replaces another element and not same element.

A single replacement reaction is one in which a more reactive element displaces a less reactive element from its salt solution. Thus one element should be different from another element.

Q6. A) $Na_3PO_4+3KOH\rightarrow 3NaOH+K_3PO_4$ , because K retains the same charge throughout the reaction

Explanation: A balanced chemical reaction is one in which the number of atoms on both sides of a chemical equation are same. Also K has an oxidation state or charge of +1 in $KOH$ as well as $K_3PO_4$

5 0

4 years ago

Read 2 more answers

What kind of energy transformations occur when you hit a coconut with a hammer

hram777 [196]

Answer: I dont really know

Explanation:

3 0

3 years ago

What is the answer???

igomit [66]

The bowl has more volume, the bearing has more volume. The mass is bigger for the bearing because it is heavier than the bowl. It is made of metal and the weight of it is greater than the bowl.(the body shape).

7 0

4 years ago