Answer:
- <em>The coefficients in a chemical equation represent the </em><u>relative number of moles of each reactant and product that interven in the chemical reaction.</u>
Explanation:
The <em>coefficients</em> are the numbers that you put in front of each chemical formula that represents the reactants and products in the <em>chemical equation</em>. They indicate the mole ratio in which the elements or compounds react to form the products, as per the chemical equation.
See an example:
- Word equation: hydrogen and oxygen produce water
- Chemical (skeleton) equation: H₂ (g) + O₂(g) → H₂O (g)
This equation is not balanced: the number of atoms of oxygenin the reactant side is 2 while the number of atoms of oxygen isn the product side is 1. In order to balance the equation you need to add some coefficients.
When no coefficients are shown it is understood that the coefficient is 1.
- Balanced chemical equation: 2H₂ (g) + O₂(g) → 2H₂O (g)
The coefficients 2 in front of H₂ and 1 (understood) in front of O₂, in the reactant side, and 2 in front of H₂O, in the product side, balance the equation.
Those coefficients mean that the 2 molecules (or mole of molecules) of H₂ react with 1 molecule (or mole of molecules) of O₂ to form 2 molecules (or moles) of H₂O (product side).
That is the mole ratio: 2 H₂ : 1 O₂ : 2 H₂O.
Notice that, in spite of the aboslute numbers may change, the mole ratio is unique for any chemical reaction. For example 4 : 2 : 4 is the same ratio that 2 : 1 : 2, or 8 : 4 : 8, but the most common practice is to use the most simple form of the ratio, i.e. 2: 1: 2.
Answer is: the energy of exactly one photon of this light is 4.75·10⁻¹⁹ J.
Photon energy equation: E = h·ν.
E - energy of one photon.
ν- frequency.
h - Planck's constant.
ν = 7.17·10¹⁴ Hz.
h = 6.63·10⁻³⁴ J·s.
E = 6.63·10⁻³⁴ J·s · 7.17·10¹⁴ Hz.
E = 4.75·10⁻¹⁹ J.
Answer: 3.59
Explanation:
(2.06)(1.743)(1.00)
2.06 × 1.743 × 1.00
= 3.59058
Two of the multiplied digits are represented in 3 significant figures. Therefore, for correct representation, the result of the product should be written to three significant figures.
3.59058 to 3 significant figures:
First three digits = 3.59
Fourth digit '0' is less than 5, and thus rounded to 0 with other succeeding digits
Therefore, (2.06)(1.743)(1.00) to 3 significant figures equals :
3.59
Answer:
Joule - J
Explanation:
As energy is defined via work, the SI unit of energy is the same as the unit of work – the joule (J).
Answer:
4380 mmHg
Explanation:
Boyle's Law can be used to explain the relationship between pressure and volume of an ideal gas. The pressure is inversely related to volume, so if volume decrease the pressure will increase. It can be expressed in the equation as:
P1V1=P2V2
In this question, the first condition is 2L volume and 876 mmHg pressure. Then the system changed into the second condition where the volume is 400ml and the pressure is unknown. The pressure will be:
P1V1= P2V2
876 mmHg * 2L = P2 * 400ml /(1000ml/L)
P2= 876 mmHg * 2L / 0.4L
P2= 4380 mmHg
