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faltersainse [42]

3 years ago

15

15 15. Which two elements will form a covalent bond?

1 answer:

Nitella [24]3 years ago

3 0

Answer:

K and Cl

Explanation:

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bogdanovich [222]

alcohol = A/A+B

= 30/100

= 0.3

5 0

3 years ago

Which of the following shows the conservation of mass during cellular respiration?

nordsb [41]

Answer:

C6 H12 O6 + 6 O2 → 6 C O2 + 6 H2 O + energy

Explanation:

6 0

3 years ago

Help meee!! this is really confusing my brain

Natasha_Volkova [10]

Answer:

I believe it's (3)

Explanation:

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6 0

2 years ago

Sodium phosphate is added to a solution that contains 0.0030 M aluminum nitrate and 0.016 M calcium chloride. The concentration

gavmur [86]

Explanation:

It is given that aluminium nitrate and calcium chloride are mixed together with sodium phosphate.

And, $K_{sp} of AlPO_{4} = 9.84 \times 10^{-21}$

$K_{sp} of Ca_{3}(PO_{4})_{2} = 2.0 \times 10^{-29}$

Let us assume that the solubility be "s". And, the reaction equation is as follows.

$AlPO_{4} \rightleftharpoons Al^{3+} + PO^{3-}_{4}$

$9.84 \times 10^{-21} = s \times s$

s = $9.92 \times 10^{-11}$

Also, $Ca_{3}(PO_{4})_{2} \rightleftharpoons 3Ca^{2+} + 2PO^{3-}_{4}$

$2 \times 10^{-29} = (3s)^{3} \times (2s)^{2}$

s = $7.14 \times 10^{-7}$

This means that first, aluminium phosphate will precipitate.

Now, we will calculate the concentration of phosphate when calcium phosphate starts to precipitate out using the $K_{sp}$ expression as follows.

$K_{sp} = [Ca^{2+}]^{3}[PO^{3-}_{4}]^{2}$

$2.0 \times 10^{-29} = (0.016)^{3}[PO^{3-}_{4}]^{2}$

$2.0 \times 10^{-29} = 4.096 \times 10^{-6} \times [PO^{3-}_{4}]^{2}$

$[PO^{3-}_{4}]^{2}$ = $4.88 \times 10^{-24}$

= $2.21 \times 10^{-12}$ M

Similarly, calculate the concentration of aluminium at this concentration of phosphate as follows.

$AlPO_{4} \rightleftharpoons Al^{3+} + PO^{3-}_{4}$

$K_{sp} = [Al^{3+}][PO^{3-}_{4}]$

$9.84 \times 10^{-21} = [Al^{3+}] \times 2.21 \times 10^{-12}$

$[Al^{3+}] = 4.45 \times 10^{-9}$ M

Thus, we can conclude that concentration of aluminium will be $4.45 \times 10^{-9}$ M when calcium begins to precipitate.

7 0

2 years ago

What is a control used for in an experiment?

Setler79 [48]

The control is what you keep the same for each one. For example if you are doing an experiment with plants say you water one with lemon juice, one with milk and one with warm water. The control would be they all have the same amount of sun light and soil. So the growing is equal to keep the experiment fair.

6 0

2 years ago