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3 years ago

How can you determine if a reacition is exothermic?

1 answer:

3 0

Exothermic reaction normally gives out heat for completing the reaction. the burning of a candle or the condensation of water vapour to water are all exothermic reactions. The prefix "ex" at the begining refers to external or outside and normally these kind of reactions release heat at the end.During neutralization, when the acida and bases are combined, it releases heat and this kind of reaction is definitely exothermic reaction.The combustion of any kind of fuel is also exothermic reaction as it gives out heat at the end.Fossil fuel burnt in cars and engines are good examples.

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Sound travels most quickly through solids because _____. solids have greater frequencies the molecules in solids are very close

uranmaximum [27]

Sound travels most quickly through solids because _____.

answer is: because solids r the most sense.

The distance between molecules in solids r very small.Because they are so close, they can collide very quickly, i.e. it takes less time for a molecule of the solid to 'bump' into its neighbor. Solids are packed together tighter than liquids and gases, hence sound travels fastest in solids.

7 0

3 years ago

Read 2 more answers

this element has an atomic number lower than that of aluminum and one less valence electrons then the Group 16 elements

ahrayia [7]

This element is nitrogen (N)

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3 years ago

If you want to produce 11 moles of NH3, how much H2 do you need?

leva [86]

Answer:

33 g of H2

Explanation:

N2 + 3 H2 -> 2 NH3

3 mol H2 -> 2 mol NH3

x -> 11 mol NH3

x= (11 mol NH3 * 3 mol H2)/ 2 mol NH3

x= 16.5 mol H2

1 mol H2 -> 2 g

16.5 mol H2 ->x

x= (16.5 mol H2 * 2 g)/ 1 mol H2

x= 33 g

3 0

3 years ago

The Xenopus laevis oocyte is roughly 1mm in diameter. After fertilization, it undergoes mitosis, a process requiring the coordin

agasfer [191]

Answer:

a) the diffusion length = 1000 micrometers;

so if the diffusion co-efficient is also known or given; we can therefore deduce the time taken( i.e how long it would take for a message to reach from one side of the cell to the other).

b) We need to be given the data value concerning the diffusion coefficient of the protein.

c) 1.234 × 10⁷ seconds

Explanation:

In a controlled transportation that occurs in diffusion; the time taken can be expressed as:

$time (t) = \frac{diffusion length^2}{diffusion co-efficient }$

Now; if a message is passed through a $Ca^{2+}$ ion, From studies; we know that these $Ca^{2+}$ ions are infinitesimally smaller in size in the $Ca^{2+}$ channels.

Also the information being carried through the $Ca^{2+}$ ions are bound to be transported diagonally across the cell.

However; the diffusion length = 1000 micrometers;

so if the diffusion co-efficient is also known or given; we can therefore deduce the time taken( i.e how long it would take for a message to reach from one side of the cell to the other).

b) Since; we don't know the information concerning the diffusion coefficient of the protein, then it is quite not possible to determine how long it would take for a message to be transmitted through the diffusion of a small protein.

c) Here; we are given the value of the diffusion coefficient to be = 0.2 micrometer²/seconds

In a transmembrane protein; the diffusion length is half the circumference of the cell which is = $\pi*r$

= $\pi * \frac{1000}{2}$

= 1570.8 micrometers

Now;the time taken can now be calculated as:

$time (t) = \frac{diffusion length^2}{diffusion co-efficient }$

$time (t) = \frac{(1570.8)^2}{0.2 }$

$time (t) =1.234*10^7 seconds$

4 0

3 years ago

4.Which sentence BEST describes the relationship between the plates in Earth's crust and the sizes of the landmasses on top of t

riadik2000 [5.3K]

Answer:

D. The plates are different in size from the landmasses.

Explanation:

The tectonic plates that are also called lithospheric plates are very massive and irregular-shaped rocks that are composed of both the continental and the oceanic lithosphere and they may vary from a few hundred to thousands of square km.

5 0

3 years ago