Do u think the ocean has valleys and mountains?explain

On July 8th, I will be 8.51472x10^8 seconds old. How old will I be in years? (Assume 365 days in a year.) Group of answer choice

KatRina [158]

Answer:

26.98

almost 27 years

5 0

3 years ago

50 Points: What is the mass of 6.12 moles of arsenic (As)?

ozzi

The mass of 6.12 moles of arsenic (As) is calculated to be approximately 459g.

HOW TO CALCULATE MASS:

The mass of a substance can be calculated by multiplying the number of moles of a substance by its molar mass. That is;

Mass of Arsenic = no. of moles of As × molar mass of As.

According to this question, 6.12 moles of arsenic was given and its molar mass is 74.92g/mol.

Mass of As = 6.12 mol × 74.92g/mol

Mass of As = 459g

Therefore, the mass of 6.12 moles of arsenic (As) is calculated to be approximately 459g.

Learn more about mass calculations at: brainly.com/question/8101390

4 0

2 years ago

Which of the reactions below are catalyzed? Check all that apply.

Verdich [7]

Answer:

B. Salt, NaCl, is produced by the process of evaporation of seawater or brine. If the surface area of the water is increased, the same volume of water evaporates faster.

C. The Haber process combines hydrogen and nitrogen to make ammonia. The two gases are passed through a reactor under pressure and at high temperatures. If iron is added to the reactor, the yield of ammonia increases.

Explanation:

Evaporation of water is responsible for the production of sodium chloride also known as table salt. Sodium and chlorine are present in water. When more evaporation of water occurs, sodium and chlorine come close together forming sodium chloride. Haber process is responsible for the production of ammonia which is used as fertilizer. For speed up the process, catalyst is used such as iron in order to complete the reaction in less time. Iron binds hydrogen and nitrogen with each other.

7 0

3 years ago

Read 2 more answers

Acetylene burns in air according to the following equation: C2H2(g) + 5 2 O2(g) → 2 CO2(g) + H2O(g) ΔH o rxn = −1255.8 kJ Given

professor190 [17]

Answer: -227 kJ

Explanation:

The balanced chemical reaction is,

$C_2H_2(g)+\frac{5}{2}O_2(g)\rightarrow 2CO_2(g)+H_2O(g)$

The expression for enthalpy change is,

$\Delta H=\sum [n\times \Delta H_f(product)]-\sum [n\times \Delta H_f(reactant)]$

$\Delta H=[(n_{CO_2}\times \Delta H_{CO_2})+ n_{H_2O}\times \Delta H_{H_2O})]-[(n_{C_2H_2}\times \Delta H_{C_2H_2})+(n_{O_2}\times \Delta H_{O_2})]$

where,

n = number of moles

$\Delta H_{O_2}=0$ (as heat of formation of substances in their standard state is zero

Now put all the given values in this expression, we get

$-1255.8=[(2\times -393.5)+(1\times -241.8)]-[(1\times \Delta H_{C_2H_2})+(\frac{5}{2}\times 0)]$

$-1255.8=[(-787)+(-241.8)]-[(1\times \Delta H_{C_2H_2})+(0)]$

$\Delta H_{C_2H_2}=-227kJ$

Therefore, the enthalpy change for $C_2H_2$ is -227 kJ.

7 0

3 years ago

Five calcite, CaCO3 (MM 100.085 g/mol), samples of equal mass have a total mass of 12.2±0.1 g . What is the average mass and abs

Westkost [7]

Answer:

The average mass of calcium in each sample is: 0.978 g

The absolute uncertainty is: 0.008 g

Explanation:

The absolute uncertainty of the total samples indicated in the statement is ± 0.1 g.

When you multiply or divide quantities with uncertainties, you calculate the final uncertanty by adding the relative uncertainties together.

The relative uncertainty is the absolute uncertainty divided by the quantity:

Relative uncertainty = 0.1g / 12.2 g = 0.008

The average mass of calcium is calculated using proportions, along with the molar masses:

Molar mass of calcium: 40.078 g/ mol (from a periodic table)

Molar mass of calcite: 100.085 g/mol (given)

Proportion:

40.078 g of calcium / 100.085 g of calcite = x / 12.2 g of calcite

x = 12.2 × 40.078 / 100.085 g = 4.89 g calcium

So the total mass of calcium in the five samples is 4.89 g, and the average mass in each sample is:

Average mass = total mass of five samples / number of samples

Average mass = 4.89 g / 5 = 0.978 g of calcium

So, the first answer is that the average mass of calcium in each sample is 0.978 g ( keep 3 signficant figures, such as the quntitiy 12.2 shows, as you have only used multiplication and division).

The absolute uncertainty of each sample is the relative uncertainty multiplied by the average mass of calcium of the five samples, rounded to one decimal:

Absolute uncertainty = 0.978 g × 0.008 ≈ 0.008 g

The answer to the secon question is that the absolute uncertaingy of calcium in each sample is 0.008 g.

7 0

3 years ago