What is the definition of PPM unit and the conversion of common units (such as mg / L, MA / kg, etc.)?

(1) 1 ppm = 1 / 1000000 = 1 × 10 ^ - 6
(2) Therefore, it is not feasible to convert to those with physical units, for example, the mg / l you mentioned; for mg / kg, 1mg / kg = 0.001g/1000g = 1ppm

What is the conversion of 0.001 mol / L lead nitrate solution to ppm and Mg / kg?

331.23 × 0.001 × 1000 = 331.2ppm (mg / L)
331.23÷1.00033123=331.1mg/kg

Calculation formula of gas flow
The customer uses 15 tons of CO2 gas every day. The pressure of our storage tank is 2.3 MPa, and the customer's demand pressure is 0.8 MPa. What is the pipe diameter we need to install? What is the flow rate of the pressure reducing valve?

And Shunda Vortex Street gas flowmeter: non streamline vortex generator is placed in the fluid, and the fluid is separated alternately on both sides of the vortex generator to release two rows of regular alternate vortex streets. Within a certain range of flow (Reynolds number), the separation frequency of vortex is proportional to the volume flow of fluid passing through the vortex street flow sensor
Where
QF is the volume flow under working condition
M 3 / S; D is the body diameter, mm; m is the ratio of the bow area on both sides of the vortex generator to the cross-sectional area of the pipe; D is the width of the upstream surface of the vortex generator, mm; F is the vortex frequency, Hz; Sr is the Strouhal number, dimensionless
Heshunda vortex flowmeter

The proportion of C40 concrete? How much sand and stones does 100 kg cement need?

C40 concrete must not be foundation or underwater concrete, and the sand ratio is between 35% - 38% (that is, there is 35% - 38% sand in each concrete volume)
For C40 concrete, 42.5 cement must be used. Under normal conditions, cement is 400-420 kg / m3, water is 160 kg, stone is 1360 kg and sand is 680 kg

The number of particles in 1 mol of different substances is equal, but the mass of 1 mol of different substances is also different. How to calculate the particle mass of 1 mol of each substance

The number of particles you mean can only be the number of molecules or atoms, not the number of protons and neutrons in atoms. So the number of 1mol water molecules is the same as that of 1mol oxygen molecules, but the mass is different. The mass is different because of the different molecular weight

The calculation formula of pipeline gas flow knows the pipeline gas pressure, such as 0.2MPa, knows the pipe diameter, such as D63, what parameters are needed and what formula is used?
List out the formula, the specific parameter, q = V * s, the formula is not correct. If it is this, you don't need to send it

Q=Dn*Dn*V*（P1+1bar）/353
Q is the standard flow rate;
DN is the pipe diameter, such as DN65, DN80 and so on, it is not necessary to convert to the inner diameter;
V is the flow rate;
P1 is the working pressure in kilobar;
When the flow rate of standard condition q is available, the condition q is easy to calculate, Q ≈ Pb / PM * q, Pb is the standard atmospheric pressure, PM = Pb + P1;
I do the natural gas pressure regulating equipment, and often involve the selection of pipe diameter. This formula is in the selection software of our company. I use it. How to calculate it is not very clear. You can try

How much sand, stone, cement and water does 100 cubic meters of concrete use?
How many cubic meters of fine sand, 5-20 mm pebbles, water and tons of cement are used for 100 cubic meters of C10 concrete?
How many cubic meters of fine sand, 5-20 mm pebble, water and tons of cement are used for 100 cubic meters of C20 concrete?
How many cubic meters of fine sand, 5-20mm pebbles, water and tons of cement are used for C25 concrete?

According to the standard of construction engineering consumption, the content is as follows:
1: How many tons of 425 cement is used for C25 concrete 100 m3, 30.80 tons for 5-20 mm pebble, 90.3 m3 for river sand and 49.8 m3 for river sand
2: 6 tons of 425 cement, 90. 3 cubic meters of 5 - 20 mm pebble and 52. 8 cubic meters of river sand
3: How many tons of 425 cement is used for 100 cubic meters of C10 concrete? 22.63 tons for 5-10 mm pebble? 72.1 cubic meters for river sand? 77.2 cubic meters for river sand

Volume table of 1mol substance
Find the volume
H2 N2 F2 liquid F2 gas Cl2 solid O2 gas Cl2 liquid O2 solid
Ar liquid Al Cl2 ar solid Fe solid SO2 gas

As long as it's gas, it's 22.4l in standard state
The density of liquid and solid can be calculated according to the density (P (ROU)) of each substance in the standard state, v = m / P (ROU). M is the relative molecular mass m × 1

Calculation formula of compressed gas flow
Pressure is 1.0MPa, pipe diameter is DN25, what is the maximum flow per minute? How to calculate? Thank you! (compressed air)

About 21.195 M & sup3; about 0.353 M & sup3 per hour and minute;

Construction workers need to make 27 tons of concrete with cement, sand and stones in a ratio of 2:3:4. How many tons of cement, sand and stones do they need?

27÷(2+3+4)=3
Cement = 2 × 3 = 6 tons
Sand = 3 × 3 = 9 tons
Stone = 4 × 3 = 12 tons

What is the definition of PPM unit and the conversion of common units (such as mg / L, MA / kg, etc.)?