Ask question

Ask question

All categories

3 years ago

5

* Why does the mass of a substance remain the same after a chemical reaction?

1 answer:

Ierofanga [76]3 years ago

5 0

ANSWER: because they are not created or destroyed they are just rearranged to form the products

You might be interested in

List three ways in witch the water reaches the atmosphere

meriva

Three ways water reaches from earth to atmosphere are
1. direct evaporation from the water bodies like sea,river,oceans
2. moisture from the land(you must have seen land dries out)
3.moisture from the plant(small capillaries from the plants sucks water from land n goes to atmosphere in form of vapour from leaves)

7 0

3 years ago

A catalyst increases the reaction rate of a reaction by (3 points)

Minchanka [31]

Answer:

A catalyst increases the rate of reaction by decreasing activation energy. ... Enzymes are highly substrate specific and catalyze reactions by providing an alternate pathway of lower activation energy.

Explanation:

I hope this helps :)

5 0

3 years ago

What is the expected freezing point of a 0.50 m solution of li2so4 in water? Kf for water is 1.86 ∘c/m.

In-s [12.5K]

Answer: -2.79°C

Explanation:

Supposing complete ionization:

Li2SO4 → 2 Li{+} + SO4{2-} [three ions]

(0.50 m Li2SO4) x 3 = 1.50 m ions

(1.50 m) x (1.86 °C/m) = 2.79°C change

0°C - 2.79°C = -2.79°C

4 0

4 years ago

Read 2 more answers

What is the empirical formula of a compound that has a pseudoformula of C3.5H8?

KIM [24]

Answer:

The ratio of carbon and hydrogen atoms = 3.5 : 8

= 7 : 16

Then,the empirical formula is C7H16

5 0

3 years ago

calculate the molarity of MgCl2 in the following solution: 5.34 g of MgCl2 is dissolved and diluted to 214 mL of solution.

anyanavicka [17]

<h3><u>Ⲁⲛ⳽ⲱⲉⲅ</u><u>:</u></h3>

$\quad\hookrightarrow\quad \sf {0.262M }$

<h3><u>Ⲋⲟⳑⳙⲧⳕⲟⲛ :</u></h3>

Molarity is used to measure the concentration of a solution , so it is also as molar concentration. It is denoted as M or Mol/L

<u>We </u><u>are </u><u>given </u><u>that </u><u>:</u>

Weight of $\sf MgCl_{2}$ = 5.34g
Volume of solution = 214 ml , or 0.214 L

The molar mass of magnesium chloride ( $\sf MgCl_{2}$ ) is 95.21 g / mol

We can calculate the molarity of the solution by dividing the number of moles of solute by volume of solvent in liter ,i.e:

$\quad\longrightarrow\quad \sf {M = \dfrac{n}{V} }$ ‎ㅤ‎ㅤ‎ㅤ⸻( 1 )

<em>Where,</em><em> </em>

M = molarity
n = number of moles
V = Volume

We can calculate the number of moles by dividing the actual mass by its molar mass ,i.e:

$\quad\longrightarrow\quad \sf { n = \dfrac{w}{m}}$ ‎ㅤ‎ㅤ‎ㅤ‎⸻ ( 2 )

<em>W</em><em>here,</em>

n = number of moles
m = molar mass
w = actual mass

<u>Therefore</u><u>,</u>

$\implies\quad \tt {n =\dfrac{w}{m} }$

$\implies\quad \tt { n =\dfrac{5.35\: g}{95.21\: g /mol}}$

$\implies\quad{\pmb{ \tt {n = 0.056 mol}} }$

<u>P</u><u>utting </u><u>the </u><u>values </u><u>in </u><u>equation </u><u>(</u><u> </u><u>1</u><u> </u><u>)</u><u>:</u>

$\implies\quad \tt {M=\dfrac{n}{V} }$

$\implies\quad \tt { M =\dfrac{0.056\:mol}{0.214\:L}}$

$\implies\quad\underline{\pmb{ \tt { M = 0.262 \:M }}}$

7 0

2 years ago