Will PCIe x1 Sound card work in PCIe x16 slot?

It's a Dell Optiplex 755 Mini Tower The PCIe slot on my PC should be a PCIe slot from what I could find

Figure shows a motherboard with two x1 PCIe, two x16 PCIe, and three PCI expansion slots Notice that the PCIe x16 slot has a retention

x1 slot Here's the best way I've found and seen of modifying a PCIE x1 slot to fit a full-sized x16 card

x16 slot I installed the adapter in the last full size PCIE slot and it works fine When installed in the x1 slot it does