Help, 8th grade Science

Chemistry

2 answers:

igor_vitrenko [27]2 years ago

6 0

It’s for sure control container

valentinak56 [21]2 years ago

5 0

Answer:

Control container

Explanation:

You might be interested in

Convert 100 miles to inches (there are 5280 ft in one mile)

expeople1 [14]

Answer:

Explanation:

100 miles * [ 5280 feet / 1 mile] * 12 inches / 1 foot]

100 * 5280 * 12 inches

6336000 inches in 100 miles

8 0

2 years ago

According to the following reaction, how many moles of chlorine gas are necessary to form 0.739 moles carbon tetrachloride? carb

Ilia_Sergeevich [38]

Answer:

2.956 moles chlorine gas will be produced

Explanation:

Step 1: data given

Number of moles carbon tetrachloride (CCl4) = 0.739 moles

carbon disulfide (s) = CS2(s)

chlorine (g) = Cl2(g)

carbon tetrachloride (l) = CCl4(l)

sulfur dichloride (s) = SCl2 (s)

Step 2: The balanced equation

CS2(s) + 4Cl2(g) → CCl4(l) +2SCl2

Step 3: Calculate moles chlorine gas

For 1 moles Cs2 we need 4 moles Cl2 to produce 1 mol CCl4 and 2 moles SCl2

For 0.739 moles CCl4 we need 4*0.739 = 2.956 moles Cl2

2.956 moles of chlorine gas will be produced

4 0

3 years ago

The half-life of radioactive substance is 2.5 minutes. what fraction of the origional radioactive remains after 10 mins

saul85 [17]

The answer is 1/16.

Half-life is the time required for the amount of a sample to half its value.
To calculate this, we will use the following formulas:
1. $(1/2)^{n} = x$ ,
where:
n - a number of half-lives
x - a remained fraction of a sample

2. $t_{1/2} = \frac{t}{n}$
where:
 $t_{1/2}$ - half-life
t - total time elapsed
n - a number of half-lives

So, we know:
t = 10 min
 $t_{1/2}$ = 2.5 min

We need:
n = ?
x = ?

We could first use the second equation to calculate n:
If:
$t_{1/2} = \frac{t}{n}$ ,
Then:
$n = \frac{t}{ t_{1/2} }$
⇒ $n = \frac{10 min}{2.5 min}$
⇒ $n=4$ 

Now we can use the first equation to calculate the remained fraction of the sample.
 $(1/2)^{n} = x$
⇒ $x=(1/2)^4$
⇒ $x= \frac{1}{16}$