3 years ago

Hard question!

Chemistry

1 answer:

sergey [27]3 years ago

6 0

Answer:as below

Explanation:Zn(NO3)2 (aq) + 2 NaOH (aq) —> Zn(OH)2 (ppt) + 2NaNO3

Zn++ + 2NO3- + 2Na++ + 2OH- —> 2NO3- + 2Na+ + Zn(OH)2

Zn++ + 2OH- —> Zn(OH)2

spectator ions are Na, NO3

You might be interested in

a chemist is studying an unknown substance he can break it into its elemental only by using chemical means.Based on this observa

Vanyuwa [196]

Answer:

Compound

Explanation:

We want to know if it's a compound or a mixture.

An example of a mixture is salt water: you can heat it hot enough to boil off the water, leaving only the salt. This is a physical change, which is how you know it's a mixture.

Something like gold is a compound: if you heat it, or hit it, you'll still only have gold. You can only break it down by chemical means, which is how you know it's a compound.

4 0

3 years ago

I really need help with this before 5:10

gtnhenbr [62]

CAN YOU HELP ME ANWSER MINE ILL HELP YOU

4 0

3 years ago

4. DBearded waste of Co-60 must be stored until it is no longer radioactive. Cobalt-60

Bingel [31]

464 g radioisotope was present when the sample was put in storage

<h3>Further explanation</h3>

Given

Sample waste of Co-60 = 14.5 g

26.5 years in storage

Required

Initial sample

Solution

General formulas used in decay:

$\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{t/t\frac{1}{2} }}}$

t = duration of decay

t 1/2 = half-life

N₀ = the number of initial radioactive atoms

Nt = the number of radioactive atoms left after decaying during T time

Half-life of Co-60 = 5.3 years

Input the value :

$\tt 14.5=No.\dfrac{1}{2}^{26.5/5.3}\\\\14.5=No.\dfrac{1}{2}^5\\\\No=\boxed{\bold{464~g}}$

8 0

3 years ago

PLZ HELP ME What are the five shared characteristics of all living things?

djverab [1.8K]

Answer:

Explanation:

I believe the answer is D.

5 0

3 years ago

Express the following quantity in scientific notation. The answer needs to have the correct number of significant figures. 21,30

melisa1 [442]

2.13 x 10 E 7 i believe this is correct

4 0

3 years ago

Read 2 more answers