A student has 5 mL of 0.300 M (NH4)2CrO4 solution. What is the concentration of NH4+ in this solution?

This number tells you the number of each type of atom in a compound.

KonstantinChe [14]

Answer:

avogadro's constant

Explanation:

this is the fixed number of the atoms in the molecule of an element

avogadro's law states that equal volumes of gases at the same temperature and pressure contain equal numbers of molecules

that is all gases with same temperature and pressure will always have equal numbers of molecules

7 0

2 years ago

Is this equation completely balanced? 2C8H8 + 25O2 8CO2 + 18H2O No, because the number of carbon, hydrogen & oxygen atoms on

Sergio039 [100]

So to make it clear let's break the equation down species by species and assess the number of each species on bothe sides of the equation:
2C₈H₈ + 25O₂ → 8CO₂ + 18H₂O
LHS: C - 16 RHS: C - 8
H - 16 H - 36
O - 50 O - 34

Thus based on that it is evident that the equation is not quite balanced. This therefore means a "No, because the number of carbon, hydrogen & oxygen atoms on both sides of the equation are not equal."

The actual balance equation would be C₈H₈ + 10O₂ → 8CO₂ + 4H₂O

8 0

2 years ago

A solution is made containing 4.6 g of sodium chloride per 250g of water.

lozanna [386]

Answer:

$\large \boxed{1.81 \, \%}$

Explanation:

$\text{Mass percent} = \dfrac{\text{mass of solute} }{\text{mass of solution}} \times 100 \, \%$

Data:

Mass of NaCl = 4.6 g

Mass of water = 250 g

Calculations:

Mass of solution = mass of NaCl + mass of water = 4.6 g + 250 g = 254.6 g.

$\text{\% m/m} = \dfrac{\text{4.6 g} }{\text{254.6 g}} \times 100 \, \% = \mathbf{1.81 \, \%}\\\\\text{The percent by mass of NaCl is $\large \boxed{\mathbf{1.81 \, \%}}$}$

3 0

2 years ago

How much heat is lost when 1277 g of H20 at 400 K is changed into ice at 263 K? Plz help I’ll give you brainliest 20 points

OLga [1]

The heat lost is $-7.32*10^-^5J$

The heat lost when the ice is cooled from 400k to 263K can be calculated using the formula of heat transfer.

<h3>Heat Transfer</h3>

This is the heat transferred from a body of higher temperature to a body of lower temperature.

$Q = mc(\delta)T$

Q = Heat Transfer
m = mass = 1277g
ΔT = change in temperature

$\delta T = (400 - 273) - (263 - 273) = \\
\delta T = T_2 - T_1\\
\delta T = -10 - 127\\
\delta T = -137^0C$

We converted the temperature from kelvin scale into Celsius scale and find the change in temperature.

Solving for heat transfer

$Q = mc\delta T\\
Q = 1277 * 4.186 * -137\\
Q = -732336.514J$

The heat loss is approximately $-7.32*10^-^5J$

Learn more on heat transfer here;

brainly.com/question/16055406

6 0

1 year ago

Which describes reproducibility

Leya [2.2K]

Reproducibility is a major principle of the scientific method. It means that a result obtained by an experiment or observational study should be achieved again with a high degree of agreement when the study is replicated with the same methodology by different researchers.

6 0

2 years ago