Answer:
(c)-He separates the larger pebbles and other debris from the finer sand by sifting it with wire mesh.
Explanation:
A mixture is an association of substances that not react between them. It can be homogeneous when it's not possible to see the substances, or heterogeneous when it's possible to see each the substances.
Randy separates the substances of the soil with a wire mesh, so it's possible to define the substances, then the mixture is heterogeneous.
electrical energy
Explanation:
electrical energy is caused by moving partial that have a negative or positive charge these purses are called electron current electricity is electrical energy that flows from one place to another usually through a wire electricity is a type of energy that comes from an electrical energy
Answer:
1.368 grams of manganese dioxide must b added to HCl to obtain 385 mL of chlorine gas.
Explanation:
Using ideal gas equation:
PV = nRT
where,
P = Pressure of chlorine gas = 
1 atm = 760 Torr
V = Volume of chlorine gas = 385 mL = 0.385 L ( 1 mL - 0.001 L)
n = number of moles of chlorine gas = ?
R = Gas constant = 0.0821 L.atm/mol.K
T = Temperature of chlorine gas =25 °C= 25 + 273 K = 300 K
Putting values in above equation, we get:


According to reaction, 1 mole of chlorine gas is obtained from 1 mole of manganese dioxide ,then 0.01573 moles of chlorine gas will be obtained from :
of manganese dioxide
Mass of 0.01573 moles of manganese dioxide:
0.01573 mol × 86.94 g/mol = 1.368 g
1.368 grams of manganese dioxide must b added to HCl to obtain 385 mL of chlorine gas.
You can use the formula: C = k - 273 to solve this problem. C stands for Celsius, and k stands for kelvin. Given the information that the Kelvin is 172k, then you can plug it into the equation and get C = (172) - 273. The correct melting point in C is -101°C. Hope this helped!
Answer:
Cold air is more dense than warm air, so when a warm air mass meets a cold air mass, the cold air ends up below the warm air. Once the air has risen, it cools and clouds can form. Weather fronts can cause clouds to form.