Can someone help w/ chem plzz

Which of the following statements is FALSE:O Density is a measure of how closely packed the atoms of a substance are.O The Densi

monitta

Answer

The Density of a substance can change if its location changes.

Explanation

All the statements are TRUE except

The Density of a substance can change if its location changes.

This is because density is an intensive property, that is regardless of the object's shape, size, or quantity, the density of that substance will always be the same. Even if you cut the object into a million pieces, they would still each have the same density.

Therefore, the statement that is FALSE is

The Density of a substance can change if its location changes.

3 0

1 year ago

Using the information in the table, calculate the number of moles in a \pu{7.89 kg}7.89 kg7, point, 89, space, k, g sample of as

Karolina [17]

We have to find the number of moles in a 7.89 kg sample of aspirin.

The formula of aspirin is: C₉H₈O₄

We are given the molar mass of C, H and O:

H: 1.008 g/mol C: 12.01 g/mol O: 16.00 g/mol

Since one molecule of aspirin has 9 atoms of C, 8 atoms of H and 4 atoms of O, and using the molar masses given, we can calculate the molar mass of aspirin:

molar mass of aspirin = 9 * 12.01 g/mol + 8 * 1.008 g/mol + 4 * 16.00 g/mol

molar mass of aspirin = 180.154 g/mol

Before we find the number of moles we can convert 7.89 kg to g. Since we know that there are 1000 g in 1 kg, we can convert it like this:

1000 g = 1 kg

mass of sample = 7.89 kg * 1000 g/1 kg

mass of sample = 7890 g

Finally, we can find the number of moles in the sample using the molar mass.

number of moles = 7890 g * 1 mol/180.154 g

number of moles = 43.795 moles

Answer: The number of moles in the sample is 43.8 moles (using 3 SF)

7 0

1 year ago

Which of the following represents positron emission? Select one: a. 3015P ---> 3014Si + ___ b. 23892U ---> 23490Th + ___ c

xxTIMURxx [149]

The simple trick which one can consider in such problem where it is asked for positron emission is :
When the atomic number goes DOWN by one and mass number remains unchanged, then a positron is emitted.

a. $P^{30}_{15} ----\ \textgreater \ Si^{30}_{14} + e^{0}_{1}^+$

Here the atomic number decreases by one.

Similarly, options b and d are eliminated.

Option c is also not the answer.
For c, Count the atomic number on left side and compare it with right side. You will see it is 9 on left and 8 on right. Atomic no. did go down by 1. But the atomic mass is changed as well.

8 0

3 years ago

Use the balanced equation given below to solve the following problem; Calculate the volume in liters of CO produced by the react

Elan Coil [88]

Answer: 40.3 L

Explanation:

To calculate the moles :

$\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}$