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3 years ago

Help guys plz help me especially with 2 and 3

Chemistry

2 answers:

goblinko [34]3 years ago

5 0

1. D) 2100 miles
2. D) 2100 m to the north west
3. B) 10.5m/s

german3 years ago

3 0

Answer:

1.D 2.D

Explanation:

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During photosynthesis, plant leaves take in carbon dioxide through _______ in their leaves. a stomata b xylem c phloem

Iteru [2.4K]

<h3>Answer:</h3>

Stomata

<h3>Explanation:</h3>

Photosynthesis refers to the process that takes place in green plants and some algae.
During the process, water and carbon dioxide are converted to nutrients or organic compounds using energy from sunlight.
The process takes place in the chloroplast on the leaves of green plants.
The water used during photosynthesis comes from the soil and then transported by xylem tissue to the leaves where the process takes place.
Carbon dioxide enters the leaves through the stomata which are the sites for gaseous exchange.
Sunlight is trapped by green pigments on the leaves known as chlorophyll.

7 0

3 years ago

Please help !!!!!!!!

Salsk061 [2.6K]

1) CH2 (gas) + Br (solid) -> BrC (solid) + H2 (gas)
2) a) CH4 + Br2 -> CH3Br + HBr
2) b) methane + bromine is substitution because one hydrogen atom from methane is replaced by one bromine atom. addition reaction takes place when one molecule combines with another to form a larger molecule so therefore a molecule from X and bromine combine to form XBr.

6 0

2 years ago

If 16.29 grams of Na2SO4 is mixed with 3.697 grams of C and allowed to react according to the balanced equation: Na2SO4(aq) + 4

abruzzese [7]

<u>Answer:</u> The limiting reagent in the given chemical reaction is carbon metal.

<u>Explanation:</u>

Excess reagent is defined as the reagent which is present in large amount in a chemical reaction.

Limiting reagent is defined as the reagent which is present in small amount in a chemical reaction. Formation of product depends on the limiting reagent.

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

<u>For sodium sulfate:</u>

Given mass of sodium sulfate = 16.29 g

Molar mass of sodium sulfate = 142 g/mol

Putting values in equation 1, we get:

$\text{Moles of sodium sulfate}=\frac{16.29g}{142g/mol}=0.115mol$

<u>For carbon:</u>

Given mass of carbon = 3.697 g

Molar mass of carbon = 12 g/mol

Putting values in equation 1, we get:

$\text{Moles of carbon}=\frac{3.697g}{12g/mol}=0.31mol$

For the given chemical reaction:

$Na_2SO_4(aq.)+4C(s)\rightarrow Na_2S(s)+4CO(g)$

By Stoichiometry of the reaction:

4 moles of carbon reacts with 1 mole of sodium sulfate

So, 0.31 moles of carbon will react with = $\frac{1}{4}\times 0.31=0.0775mol$ of sodium sulfate

As, given amount of sodium sulfate is more than the required amount. So, it is considered as an excess reagent.

Thus, carbon metal is considered as a limiting reagent because it limits the formation of product.

Hence, the limiting reagent in the given chemical reaction is carbon metal.

4 0

3 years ago

Dilution question In many of the experiments, you will be asked to prepare a standard solution by diluting a stock solution. You

riadik2000 [5.3K]

Answer:

We could do two 1:50 dilutions and one 1:4 dilutions.

Explanation:

Hi there!

A solution that is 1000 ug/ ml (or 1000 mg / l) is 1000 ppm.

Knowing that 1 ppm = 1000 ppb, 100 ppb is 0.1 ppm.

Then, we have to dilute the stock solution (1000 ppm / 0.1 ppm) 10000 times.

We could do two 1:50 dilutions and one 1:4 dilutions (50 · 50 · 4 = 10000). Since the first dilution is 1:50, you will use the smallest quantity of the stock solution (if we use the 10.00 ml flask):

First step (1:50 dilution):

Take 0.2 ml of the stock solution using the third dispenser (20 - 200 ul), and pour it in the 10.00 ml flask. Fill with water to the mark (concentration : 1000 ppm / 50 = 20 ppm).

Step 2 (1:50 dilution):

Take 0.2 ml of the solution made in step 1 and pour it in another 10.00 ml flask. Fill with water to the mark. Concentration 20 ppm/ 50 = 0.4 ppm)

Step 3 (1:4 dilution):

Take 2.5 ml of the solution made in step 3 (using the first dispenser 1 - 5 ml) and pour it in a 10.00 ml flask. Fill with water to the mark. Concentration 0.4 ppm / 4 = 0.1 ppm = 100 ppb.

6 0

3 years ago

Balance the following equations by inserting the proper coefficients.

Montano1993 [528]

1212. 1212. 1323........

6 0

3 years ago

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