How many Joules are there in 55 nutritional calories?

What is the Energy of a wave whose frequency is 8.45 x 10^14 Hz?

allsm [11]

Answer:

E = hf

E = hc/lamda

where E-energy,

h-planck's constant (6.62 x 10^-34 Js)

f- frequency ( f = c/lamda)

c-velocity of light ( 3 x 10^8 m/s)

lamda- wavelength

you can this formula to solve all the 4 questions.

8 0

3 years ago

8

Roman55 [17]

Answer:

305 litres of NO gas will be produced from 916 L of NO₂

Explanation:

Given the balanced equation of the chemical reaction as follows:

3 NO₂ (g) + H₂O( l) —— 2 HNO₃ (l) + NO (g)

Under standard conditions, 3 moles of No₂ will react with 1 mole of water to produce 1 mole of NO gas.

Molar volume of a gas at STP is 22.4 L

Number of moles of NO₂ gas present in 916 L = 916/22.4 = 40.893 moles of NO₂ gas

From the mole ratio of NO₂ to NO in the equation of reaction,

Number of moles of NO that will be produced = 1/3 × 40.893 moles = 13.631 moles of NO gas

Volume of 13.631 moles of NO gas = 13.631 × 22.4

Volume of NO gas produced = 305.334L

Therefore, Volume of NO gas produced from the reaction of 916 L of NO₂ with water = 305 L

5 0

2 years ago

Name the functional group in the following molecule: H-C(Triple Bond)C-CH2CH3

Dima020 [189]

Here is your answer

Since, carbon atoms are triple bonded.

So functional group present in the compound is ALKYNE

HOPE IT IS USEFUL

3 0

3 years ago

g When aqueous solutions of and are mixed, a solid forms. Determine the mass of solid formed when 140.7 mL of 0.1000 M is mixed

solong [7]

The question is incomplete, the complete question is:

When aqueous solutions of NaCl and $Pb(NO_3)_2$ are mixed, a solid forms. Determine the mass of solid formed when 140.7 mL of 0.1000 M NaCl is mixed with an excess of an aqueous solution of

Answer: The mass of lead chloride produced is 1.96 g

Explanation:

Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L. The formula used to calculate molarity:

$\text{Molarity of solution}=\frac{\text{Moles of solute}\times 1000}{ \text{Volume of solution (mL)}}$ .....(1)

Given values:

Molarity of NaCl = 0.1000 M

Volume of the solution = 140.7 mL

Putting values in equation 1, we get:

$0.1000=\frac{\text{Moles of NaCl}\times 1000}{140.7}\\\\\text{Moles of NaCl}=\frac{0.1000\times 140.7}{1000}=0.01407mol$

The chemical equation for the reaction of NaCl and lead nitrate follows:

$Pb(NO_3)_2(aq)+2NaCl(aq)\rightarrow PbCl_2(s)+2NaNO_3(aq)$

By the stoichiometry of the reaction:

If 2 moles of NaCl produces 1 mole of lead chloride

So, 0.01407 moles of NaCl will produce = $\frac{1}{2}\times 0.01407=0.007035mol$ of lead chloride

The number of moles is defined as the ratio of the mass of a substance to its molar mass.

The equation used is:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ ......(2)

Molar mass of lead chloride = 278.1 g/mol

Plugging values in equation 2:

$\text{Mass of lead chloride}=(0.007035mol\times 278.1g/mol)=1.96g$

Hence, the mass of lead chloride produced is 1.96 g

8 0

3 years ago

-FeS2+-O2->-Fe2O3+-SO2 What coefficient should be placed in front of SO2 to balance the equation?

NISA [10]

Answer:

8 should be placed in front of SO₂.

Explanation:

The easiest way to solve this question is by writing the entire balanced equation:

4FeS₂ + 11O₂ -> 2Fe₂O₃ + 8SO₂

We can achieve this by first balancing the Fe, then S, and finally the O.

We can also double check our answer by counting the number of each element on both sides:

-Reactants: 4 Fe, 8 S, 22 O

-Products: 4 Fe 8 S, 22 O

Since they match, our equation is balanced, and the coefficient in front of SO₂ is 8.

8 0

3 years ago