Like Earth, the moon

Someone please help fast

Volgvan

Answer:

The last region should be right

Explanation:

3 0

3 years ago

For the reaction H2PO4- HAsO4 2-HPO4 2-+H2AsO4- <br> what species are a conjugate acid-base pair?

aleksklad [387]

Ionic equation:

$\text{H}_2\text{PO}_4^{-} + \text{HAsO}_4^{2-} \to \text{HPO}_4^{2-} + \text{H}_2\text{AsO}_4^{-}$

The acid and base in a conjugate pair differ by only one proton $\text{H}^{+}$ . The acid loses one proton to produce a conjugate base, whereas the base gains a proton to produce its conjugate acid.

$\text{H}_2\text{PO}_4^{-}$ loses one proton to produce $\text{HPO}_4^{2-}$ in this reaction.

$\text{H}_2\text{PO}_4^{-} \to \text{H}^{+} + \text{HPO}_4^{2-}$

Meanwhile, $\text{HAsO}_4^{2-}$ gains one proton to form $\text{H}_2\text{AsO}_4^{-}$ .

$\text{HAsO}_4^{2-} + \text{H}^{+} \to \text{H}_2\text{AsO}_4^{-}$

Therefore

$\text{H}_2\text{PO}_4^{-}$ is the conjugate acid $\text{HPO}_4^{2-}$ , its conjugate base.
$\text{HAsO}_4^{2-}$ is the conjugate base of $\text{H}_2\text{AsO}_4^{-}$ , its conjugate acid.

8 0

3 years ago

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1) The heat of combustion for the gases hydrogen, methane and ethane are −285.8, −890.4 and −1559.9 kJ/mol respectively at 298K.

Morgarella [4.7K]

Answer:

The enthalpy of the reaction is 64.9 kJ/mol.

Explanation:

$H_2 + \frac{1}{2}O_2\rightarrow H_2O,\Delta H_1 =-285.8 kJ$ ..[1]

$CH_4 + 2O_2\rightarrow CO_2 + 2H_2O,\Delta H_2 =-890.4 kJ$ ..[2]

$C_2H_6 + \frac{7}{2}O_2\rightarrow 2CO_2 + 3H_2O,\Delta H_3= -1559.9 kJ$ ..[3]

$2CH_4(g)\rightarrow C_2H_6(g) + H_2(g),\Delta H_4=?$ ..[4]

2 × [2] - [1]- [3] = [4] (Using Hess's law)

$\Delta H_4=2\times \Delta H_2 -\Delta H_1 -\Delta H_3$

$\Delta H_4=2\times (-890.4 kJ)-(-285.8 kJ) -(-1559.9 kJ)$

$\Delta H_4=64.9 kJ/mol$

The enthalpy of the reaction is 64.9 kJ/mol.

3 0

3 years ago

A substance is found to consist of 1.900g of silver, 0.250g of nitrogen, and 0.850g of oxygen. what is the percent by mass of ox

Galina-37 [17]

The percentage by mass of oxygen in the compound

find the total mass=( 1.900+ 0250 +0.850) = 3
the percentage mass mass of oxgyen/total mass x100

that is (0.850/3) x100=28.33%

7 0

3 years ago

Put the following names in the correct alphabetic indexing order:(1) Topper & Casey Plumbing(2) KST Enterprises(3) Leland an

dangina [55]

Answer: the correct option is 2, 3, 4, 1.

Explanation:alphabetic indexing order is the order in which files or names are being arranged according to the alphabet. In the following names:

2) KST Enterprises

3)Leland and Son Graphics

4)Lucinda Topper

1) Topper & Casey Plumbing.

While arranging alphabetically, the first letters are usually considered but in a scenario where alphabet occurs twice( 3 And 4) the second letter is considered. I hope this helps, thanks

5 0

3 years ago

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