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lions [1.4K]
3 years ago
8

What happens to the influenza virus every 20-40 years, and why? What are the recent example(s)?

Chemistry
1 answer:
LenKa [72]3 years ago
8 0

Answer:

The influenza virus is mutated every 20-40 years.

Explanation:

Large mutations occur every 20-40 years. This results in a new influenza virus to  which the human population has no protection. These large mutations are almost always followed by an influenza pandemic.

Hope this helps!

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The density of the hydrocarbon in part (a) is 2.0 g l-1 at 50°c and 0.948atm. (i) calculate the molar mass of the hydrocarbon. (
Vedmedyk [2.9K]

1. Answer;

=56 g/mol

Explanation and solution;

PV = nRT

nRT= mass/molar mass (RT)

molar mass = (mass/V ) × (RT/P)

                   = Density × (RT/P)

Molar mass = 2.0 g/L × (0.0821 × 323 K)/0.948 atm

Molar mass = 56 g/mol


2. Answer;

Molecular mass is C4H8

Explanation;

Empirical mass × n = molar mass

Empirical mass for CH2 = 14 g/mol

Therefore;

56 g/mol = 14 g/mol × n

   n = 4

The molecular formula= 4(CH2)

    = C4H8


7 0
2 years ago
How does the use of hydroelectric energy compare to the use of coal?
lora16 [44]
<span>Hydroelectric energy uses the movement of water to spin a turbine and produce electricity. Coal is a fossil fuel that is burned as an energy source, which results in emissions such as carbon dioxide, nitrogen, and sulfur. Coal use is associated with waste products both from the mining process to acquire the coal and also from the actual use of coal itself. Hydroelectric energy does not involve waste, but does pose potential problems to waterways. Coal use is more common than the use of hydroelectric energy.</span>
4 0
3 years ago
Please Help I will reward brainliest
8_murik_8 [283]
I think it is "Known".

Radioactive decay is measured using a formula where the half-life <span>of an isotope is the time it takes for the original nuclei to decay half of its original amount.</span>
7 0
3 years ago
Read 2 more answers
Phosphorus trichloride gas and chlorine gas react to form phosphorus pentachloride gas: PCl3(g)+Cl2(g)⇌PCl5(g). A 7.5-L gas vess
Tpy6a [65]

Answer:

The equilibrium constant in terms of concentration that is, K_c=3.6243\times 10^{3} .

Explanation:

PCl_3(g)+Cl_2(g)\rightleftharpoons PCl_5(g)

The relation of K_c\& K_p is given by:

K_p=K_c(RT)^{\Delta n_g}

K_p= Equilibrium constant in terms of partial pressure.=98.1

K_c= Equilibrium constant in terms of concentration  =?

T = temperature at which the equilibrium reaction is taking place.

R = universal gas constant

\Delta n_g = Difference between gaseous moles on product side and reactant side=n_{g,p}-n_{g.r}=1-2=-1

98.1=K_c(RT)^{-1}

98.1 =\frac{K_c}{RT}

K_c=98.1\times 0.0821 L atm/mol K\times 450 K=3,624.30=3.6243\times 10^{3}

The equilibrium constant in terms of concentration that is, K_c=3.6243\times 10^{3} .

5 0
3 years ago
Read 2 more answers
The molarity of a solution prepared by dissolving 4.11 g of NaI in enough water to prepare 312 mL of solution is
Dimas [21]

Answer:

The correct answer is 8.79 × 10⁻² M.

Explanation:

Based on the given information, the mass of NaI given is 4.11 grams. The molecular mass of NaI is 149.89 gram per mole. The moles of NaI can be determined by using the formula,

No. of moles of NaI = Weight of NaI/ Molecular mass

= 4.11 / 149.89

= 0.027420

The vol. of the solution given is 312 ml or 0.312 L

The molarity can be determined by using the formula,

Molarity = No. of moles/ Volume of the solution in L

= 0.027420/0.312

= 0.0879 M or 8.79 × 10⁻² M

6 0
2 years ago
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