Convert 100 m/s into miles per hour. 100 m/s =

11mg of cyanide per kilogram of body weight is lethal for 50% of domestic chickens. How many grams per kilogram of body weight i

Nookie1986 [14]

Answer:

$0.033g$

Explanation:

Hello,

In this case, since 11 mg per kilogram of body weight has the given lethality, the mg that turn out lethal for a chicken weighting 3 kg is computed by using a rule of three:

$11mg\longrightarrow 1kg\\\\x\ \ \ \ \ \ \longrightarrow 3kg$

Thus, we obtain:

$x=\frac{3kg*11mg}{1kg}\\ \\x=33mg$

That in grams is:

$=33mg*\frac{1g}{1000mg} \\\\=0.033g$

Regards.

7 0

3 years ago

The half-life of Palladium-100 is 4 days. After 12 days a sample of Palladium-100 has been reduced to a mass of 4 mg. What was t

Degger [83]

Answer : The initial mass of the sample is, 31.9 mg

Explanation :

Half-life = 4 days

First we have to calculate the rate constant, we use the formula :

$k=\frac{0.693}{t_{1/2}}$

$k=\frac{0.693}{4\text{ days}}$

$k=0.173\text{ days}^{-1}$

Now we have to calculate the initial mass of sample.

Expression for rate law for first order kinetics is given by:

$t=\frac{2.303}{k}\log\frac{a}{a-x}$

where,

k = rate constant = $0.173\text{ days}^{-1}$

t = time passed by the sample = 12 days

a = initial amount of the reactant = ?

a - x = amount left after decay process = 4 mg

Now put all the given values in above equation, we get

$12=\frac{2.303}{0.173}\log\frac{a}{4}$

$a=31.9mg$

Therefore, the initial mass of the sample is, 31.9 mg

3 0

4 years ago

A solution contains 1.817 mg of CoSO4 (155.0 grams/mole) per mL. Calculate the volume (in mL) of 0.009795 M Zn2 needed to titrat

Nana76 [90]

Answer:

85.952 ml $Zn^2^+$ needed to titrate the excess complexing reagent .

Explanation:

Lets calculate

After addition of 80 ml of EDTA the solution becomes = 20 + 70 = 90 ml

As the number of moles of $CoSO_4$ = $\frac{Given mass }{molar mass}$

= $\frac{1.817}{155}$

=0.01172

Molarity = $\frac{no. of moles}{volume of solution}$

= $\frac{0.01172}{20}$

=0.000586 moles

Excess of EDTA = concentration of EDTA - concentration of CoSO4

= 0.009005 - 0.000586

= 0.008419 M

As M1V1 ( Excess of EDTA ) = M2V2 $(Zn^2^+)$

$0.008419\times100ml=0.009795\times V2$

$V2=\frac{0.008419\times100}{0.009795}$

V2 =85.952 ml

Therefore , 85.952 ml $Zn^2^+$ needed to titrate the excess complexing reagent .

3 0

3 years ago

Beth’s hygrometer is reading a temperature of 30°C and a relative humidity of 65%. The humidity in the air is how many grams/cub

emmasim [6.3K]

This is asking for the absolute humidity. So if the relative humidity is 65 % and the air temperature is 30 then we need to have in mind the barometric pressure which will be 760. The humidity in the air will be 0.020 kg/m3. In order to know this we calculate it eith the mass of water vapour in a unit volume of air. This is a measure of the actual water vapour content of the air. the for mula would go like this: AH = Mv / V.

5 0

3 years ago

Assume you have 4 solids (A, B, C and D) of similar mass. Which of these requires the greatest energy input to melt?

bazaltina [42]

The solid that require the greatest energy input to melt by mass is the option;

Covalent network

Solution Explanation

The elementary particles of a solid are held together by bonds that require an input of energy to unlock, and once broken, the particles are then able to change location within their containing vessels with less restrictions

Polar covalent molecular solids have the following characteristics;

a) Soluble in water b) Low melting point, b) Conduct electricity

Solids that are made up of a covalent network have the following characteristics

a) High melting point temperature b) Non conductive of electricity c) Not soluble in water

Solids of ionic compounds have the following characteristics;

a) High melting point temperature b) The liquid state and solution conducts electricity c) Soluble in water

Solids that have nonpolar covalent bonds have;

a) Low melting point b) Normally in the gaseous or liquid state b) Not water soluble

The covalent network, and the solids ionic compounds require the most energy to melt, however, the strength of the ionic bond in an ionic compound is a factor the charges present and the sizes of the atom, while the covalent network solid, are combined to form essentially as a single molecule and therefore require the greatest heat energy input to melt

7 0

4 years ago