All categories

2 years ago

Help….? Anyone? It’s a test. 99 points

Chemistry

2 answers:

Crazy boy [7]2 years ago

7 0

Answer:

Cyanobacterium

Explanation:

“Cyanobacterium” is the correct answer, as it has the kingdom bacteria in its name.

Naily [24]2 years ago

6 0

which organism is a member of Kingdom Eubacteria?

CYANOBACTERIUM

➜ are classified in the kingdom Monera. considered to be more closely related to bacteria and are no longer considered members of the plant family.

$\tiny\bold\orange{{❀도움이 되기를 바랍니다❀}}$

You might be interested in

Doctors sometimes use computer models to track the spread of an infectious disease . How might this help them better understand

kotegsom [21]

It could them know how it start when it started wats in the infectious disease and why

7 0

3 years ago

Keera decided to investigate how the growth of plants is affected by the time of day it is watered. She placed an equal amount o

Arada [10]

The time of day the plants are watered is the independent variable. Keera did everything else the same for each plant.

7 0

3 years ago

What does a mole of iron weigh

r-ruslan [8.4K]

As the atomic mass of iron is 55.847u

We say that it is the mass of one mole of iron.

By formula it can be find by

No.of mole=mass in g/molar mass

Mass in gram = no.of mole x molar mass

No.of mole =1

Molar mass = 55.847g

Mass in gram = 1x55.847

= 55.847g of Fe

3 0

3 years ago

A mixture of CO2 and Kr weighs 41.0 g and exerts a pressure of 0.729 atm in its container. Since Kr is expensive, you wish to re

Elena-2011 [213]

Answer:

a) 24.31 g

b) 16.69 g

Explanation:

A mixture of CO2 and Kr weighs 41.0 g and exerts a pressure of 0.729 atm in its container.

After the CO2 is completely removed by absorption with NaOH(s), the pressure in the container is 0.193 atm.

Therefore, Pressure of Kr = 0.193 atm

Pressure of CO2 = 0.729 - 0.193 = 0.536 atm

Their mole fraction can be also determined as follows:

CO2 = $\frac{Presssure due to CO_2}{Total pressure}$

CO2 = $\frac{0.536}{0.729}$

= 0.735

Also; for Kr ; we have

Kr = $\frac{0.193}{0.729}$

Kr = 0.265

Molar mass of CO2 = 44 g/mol

Molar mass of Kr = 83.78 g/mol

Mass of CO2 = mole fraction * molar mass = 0.735 * 44 = 32.34

Mass of Kr = 0.265 * 83.78 = 22.20

Total mass = 32.34 +22.20 = 54.54

The Percentage of gas in mixture is as follows:

% CO2 = $\frac{32.34}{54.54}$ * 100 %

= 0.5930

= 59.30%

(a) Mass of CO2 in mixture = 0.5930* 41 g = 24.31 g

% Kr = $\frac{22.20}{ 54.54}$ * 100 %

= 0.407

= 40.70 %

(b) Mass of Kr in mixture = 0.407 * 41 = 16.69 g

4 0

3 years ago

A laboratory technician needs to prepare 500 milliliters of a 2 M solution of sodium hydroxide (NaOH) in a flask. The flask has

Marat540 [252]

Answer:

40 g NaOH

Step-by-step explanation:x

To make 500 mL of a 2 mol·L⁻¹ solution, the technician must measure the correct mass of NaOH.

Step 1. Calculate the moles of NaOH

c = n/V Multiply both sides by V

n = Vc

c = 2 mol·L⁻¹

V =0.5 L

n = 0.5 × 2

n = 1 mol NaOH

Step 2. Calculate the mass of NaOH

The molar mass of NaOH is 40.00 g/mol.

m = 1 × 40.00/1

m = 40 g NaOH

The technician must measure 40 g of NaOH.

4 0

3 years ago

Read 2 more answers