Answer:
this may help you solve the problem! :D
Explanation:
Negative air ions (NAIs) have been discovered for more than 100 years and are widely used for air cleaning. Here, we have carried out a comprehensive reviewing on the effects of NAIs on humans/animals, and microorganisms, and plant development. The presence of NAIs is credited for increasing psychological health, productivity, and overall well-being but without consistent or reliable evidence in therapeutic effects and with controversy in anti-microorganisms. Reports also showed that NAIs could help people in relieving symptoms of allergies to dust, mold spores, and other allergens. Particulate matter (PM) is a major air pollutant that affects human health. Experimental data showed that NAIs could be used to high-efficiently remove PM. Finally, we have reviewed the plant-based NAI release system under the pulsed electric field (PEF) stimulation.
Answer: The wire is still copper and does not change by cutting it
Explanation:
Democritus postulated that all materials were composed of these tiny particles called as "atomos".
Daltons postulates are:.
1. All matter is made of very tiny particles called atoms.
2. Atoms is indivisible.
3. Atoms of a given element are identical in mass and chemical properties.
4. Atoms of different elements have different masses and chemical properties.
5. Atoms combine in the ratio of small whole numbers to form compounds.
6. The relative number and kinds of atoms are constant in a given compound.
Thus when copper wire is cut into the smallest possible pieces, the atoms were intact as they are indivisible and all atoms have same mass and chemical properties.Thus the wire is still copper and does not change by cutting it
Answer:
150.000 g
Explanation:
The law of conservation of mass states that the mass of reactants and products of a reaction must be equal to one another.
In other words, for this case:
- Mass of KOH + Mass of HCl = Mass of Products
We are given all required data to<u> calculate the mass of the KOH solution</u>:
- Mass of KOH + 250.000 g = 400.000 g
The answer is Sulfuric acid
Answer:
817.66 g/mol
Explanation:
The <em>freezing point change</em> can be calculated by the formula:
Where m is the molality of the solute in NO, Kf is the cryoscopic constant (in K·kg/mol), and i is 1 in this case (because the substance in non-dissociating).
We can <u>calculate Kf of NO</u> with the information given by the problem and the formula:
Where R is the universal gas constant (8.314 J·mol⁻¹·K⁻¹), M is the molar mass of NO (30 g/mol, or 0.03 kg/mol), T f is the freezing point of NO (in K), and ΔH is the heat of fusion.
- Kf = 8.314 J·mol⁻¹·K⁻¹ * 0.03 kg/mol * (109.16 K)² ÷ 2300 J/mol = 1.292 K·kg/mol
Now we calculate the molality of the solute in NO:
<em>Molality is equal to the moles of solute per kilogram of solvent</em>:
- 0.1370 m = moles solute/ 1 kg NO
- moles solute = 0.1370 moles
With the given mass of the solute we <u>can calculate the molar mass</u>:
- 112 g / 0.1370 moles = 817.66 g/mol