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3 years ago

About how many times longer than modern humans have hooved mammals lived on earth?

Chemistry

1 answer:

abruzzese [7]3 years ago

8 0

Answer:

I think it should be about maybe the times of the dinosaurs

also I think 23 to 16 billion years

Explanation:

No explanation sorry if im wrong

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Which compound contains a triple bond?

Igoryamba

There are many compounds which contain triple bonds between two atoms. Few of the are as follow,

Nitrogen Molecule:

   N₂ or :N≡N:

Cyanide Ion:

  CN⁻ or [:C≡N:]⁻

Alkynes:
   R-C≡C-R

Carbon Monoxide:

CO or :C≡O:

Among given compounds Alkynes belong to a class of unsaturated hydrocarbons. The carbon atom in alkyne is sp hybridized. These unsaturated hydrocarbons have their own characteristic chemical properties.

6 0

3 years ago

Read 2 more answers

A sample was prepared by mixing 18. ml of 3.00 x 10^-3 m crystal violet (cv) with 2.00 ml of 0.250 m naoh. calculate the resulti

Aleks [24]

Answer : The resulting concentrations of CV and NaOH are 0.0027 M and 0.025 M respectively.

Explanation :

Step 1 : Find moles of crystal violet and NaOH.

The molarity formula is

$Molarity = \frac{mol}{L}$

Molarity of crystal violet = $3.00 \times 10^{-3} = \frac{mol (CrystalViolet)}{L}$

The volume of crystal violet solution is 18 mL which is 0.018 L.

Moles of crystal violet = $3.00 \times 10^{-3} \times 0.018 = 5.4 \times 10^{-5}$

Moles of crystal violet = 5.4 x 10⁻⁵

Moles of NaOH = $Molarity \times L = 0.250 \times 0.00200 = 5.00 \times 10^{-4}$

Moles of NaOH = 5.00 x 10⁻⁴

Step 2 : Find total volume of the solution

The total volume of the solution after mixing NaOH and crystal violet is

0.018 L + 0.00200 = 0.020 L

Step 3 : Use molarity formula to find final concentrations

Molarity of crystal violet = $\frac{mol(CrystalViolet)}{Total Volume(L) } = \frac{5.4 \times 10^{-5}}{0.020} = 2.7 \times 10^{-3}$

Final concentration of CV = 0.0027 M

Molarity of NaOH= $\frac{mol(NaOH)}{Total Volume(L) } = \frac{5.00 \times 10^{-4}}{0.020} = 0.025 \times 10^{-3}$

NaOH is a strong base and dissociates completely as follows.

$NaOH (aq) \rightarrow Na^{+} (aq) + OH^{-} (aq)$

The mole ratio of NaOH and OH⁻ is 1:1 . Therefore the concentration of OH⁻ is same as that of NaOH.

Concentration of OH⁻ = 0.025 M

8 0

3 years ago

If 10.57 g of magnesium reacts completely with 6.96 g of oxygen, what is the percent by mass of oxygen in magnesium oxide? Round

Deffense [45]

Answer:

39.7 %

Explanation:

magnesium + oxygen ⟶ magnesium oxide

10.57 g 6.96 g 17.53 g

According to the <em>Law of Conservation of Mass</em>, the mass of the product must equal the total mass of the reactants.

Mass of MgO = 10.57 + 6.96

Mass of MgO = 17.53 g

The formula for mass percent is

% by mass = Mass of component/Total mass × 100 %

In this case,

% O = mass of O/mass of MgO × 100 %

Mass of O = 6.96 g

Mass of MgO = 17.53 g

% O = 6.96/17.53 × 100

% O = 0.3970 × 100

% O = 39.7 %

5 0

3 years ago

The following reaction is exothermic. C6H12O6(s)+6O2(g)⇌6CO2(g)+6H2O(g)C6H12O6(s)+6O2(g)⇌6CO2(g)+6H2O(g) Predict the effect (shi

elena55 [62]

Answer:

According to Le Chatelier's principle, increasing the reaction temperature of an exothermic reaction causes a shift to the left and decreasing the reaction temperature causes a shift to the right.

Explanation:

C6H12O6(s) + 6O2(g) ⇌6CO2(g) + 6H2O(g)

We are told that the forward reaction is exothermic, meaning heat is removed from the reacting substance to the surroundings.

According to Le Chatelier's principle,

1. for an exothermic reaction, on increasing the temperature, there is a shift in equilibrium to the left and formation of the product is favoured.

2. if the temperature of the system is decreased, the equilibrium shifts to right and the formation of the reactants is favoured.

3. if the reaction temperature is kept constant, the system is at equilibrium and there is no shift to the right nor to the left.

4 0

3 years ago

Read 2 more answers

Plxzzzzzzzzzzzzzzzzzz

katrin [286]

The correct answers is 1/57

5 0

2 years ago