Lead (II)oxide+calcium metal=

Scientist looking for new substances in plants grind up the plants with methanol. This solvent dissolves many plant compounds. H

liubo4ka [24]

Answer:

See explanation

Explanation:

Crystals can be made from methanol by recrystallizing the plant extract from methanol.

The methanol/water system is heated rapidly using a hot plate and the plant extract dissolves in the heating solution until a clear solution is obtained.

The solution is now cooled rapidly. The interior of the flask used for the re crystallization may even by scratched to assist the quick formation of crystals. Large crystals of plant compounds may be obtained using this method. This process should be carried out in a fume hood because of the toxicity of methanol.

4 0

2 years ago

Determine if the equation is endothermic or exothermic examples

Fittoniya [83]

There are a couple of ways todetermine if a reaction is exothermic or endothermic. Endothermic meaning that heat is added to the reaction to make the reactants interact and exothermic meaning heat is released during the reaction between the two reactants.

In endothermic reactions you can find a triangle above the arrow.

6 0

2 years ago

An alloy with an average grain diameter of 35 μm has a yield strength of 163 Mpa, and when it undergoes strain hardening, the gr

Lera25 [3.4K]

Answer:

$\sigma_y\ =210.2\ MPa$

Explanation:

Given that

d= 35 μm ,yield strength = 163 MPa

d= 17 μm ,yield strength = 192 MPa

As we know that relationship between diameter and yield strength

$\sigma_y=\sigma_o+\dfrac{K}{\sqrt d}$

$\sigma_y\ =Yield\ strength$

d = diameter

K =Constant

$\sigma_o\ =material\ constant$

So now by putting the values

d= 35 μm ,yield strength = 163 MPa

$163=\sigma_o+\dfrac{K}{\sqrt 35}$ ------------1

d= 17 μm ,yield strength = 192 MPa

$192=\sigma_o+\dfrac{K}{\sqrt 17}$ ------------2

From equation 1 and 2

$192-163=\dfrac{K}{\sqrt 17}-\dfrac{K}{\sqrt 35}$

K=394.53

By putting the values of K in equation 1

$163=\sigma_o+\dfrac{394.53}{\sqrt 35}$

$\sigma_o\ =96.31\ MPa$

$\sigma_y=96.31+\dfrac{394.53}{\sqrt d}$

Now when d= 12 μm

$\sigma_y=96.31+\dfrac{394.53}{\sqrt 12}$

$\sigma_y\ =210.2\ MPa$

4 0

2 years ago

which of the following statements correctly describes the relative masses of the particles in atoms

zysi [14]

Answer:

protons and neutrons

Explanation:

protons and neutrons is equal to mass number

6 0

2 years ago

Identify the solute and solvent in a solution made from 15 mL of oxygen and 5 mL of helium.

Marina CMI [18]

Answer:

Oxygen is solvent and Helium is solute.

Explanation:

Helium is a complety inert gas which do not react with other compounds whereas, oxygen can take part in chemical reaction with many compounds.

if we mix 15 mL of oxygen and 5mL of helium then the oxygen is the solvent and helium is solute.
In a mixture the compound with the greater volume is solvent and the compound with lwss volume is solute.
in this case, oxygen has greater volume than that of helium so oxygen is solute and helium is solvent here.

6 0

2 years ago

Lead (II)oxide+calcium metal=​

Lead (II)oxide+calcium metal=